Compositions and methods comprising glycyl-tRNA synthetases having non-canonical biological activities

ABSTRACT

Isolated glycyl-tRNA synthetase polypeptides and polynucleotides having non-canonical biological activities are provided, as well as compositions and methods related thereto.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.13/753,272 filed Jan. 29, 2013, now allowed; which is a Continuation ofU.S. application Ser. No. 12/492,925 filed Jun. 29, 2009, now U.S. Pat.No. 8,404,471, issued Mar. 26, 3013; which claims the benefit under 35U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/095,548filed Sep. 9, 2008; and U.S. Provisional Patent Application No.61/076,098 filed Jun. 26, 2008, which are incorporated herein byreference in their entireties.

STATEMENT REGARDING SEQUENCE LISTING

The Sequence Listing associated with this application is provided intext format in lieu of a paper copy, and is hereby incorporated byreference into the specification. The name of the text file containingthe Sequence Listing is ATYR_008_04US_ST25. The text file is 23 KB, wascreated on Apr. 28, 2014 and is being submitted electronically viaEFS-Web, concurrent with the filing of the specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to glycyl-tRNA synthetase(GlyRS) polypeptides, compositions comprising such polypeptides, andmethods of using same.

2. Description of the Related Art

Aminoacyl-tRNA synthetases, which catalyze the aminoacylation of tRNAmolecules, are essential for decoding genetic information during theprocess of translation. Each of the eukaryotic tRNA synthetases consistsof a core enzyme, which is closely related to the prokaryoticcounterpart of the tRNA synthetase, and an additional domain that isappended to the amino-terminal or carboxyl-terminal end of the coreenzyme. Human tyrosyl-tRNA synthetase (TyrRS), for example, has acarboxyl-terminal domain that is not part of prokaryotic and lowereukaryotic TyrRS molecules.

Several aminoacyl-tRNA synthetases have been demonstrated to havenon-canonical functions distinct from their involvement in translation.For example, mini-tyrosyl tRNA synthetase (mini-TyrRS), the N-terminaldomain of TyrRS which corresponds to amino acid residues 1-364 and iscleaved by polymorphonuclear cell elastase and plasmin, exhibitsnon-canonical biologies not found in the full-length protein. In vitro,mini-TyrRS has been shown to stimulate neutrophil activation andchemotaxis, endothelial cell proliferation and migration, and ispro-angiogenic in chick chorioallantoic membrane (CAM) and mousematrigel assays. Mini-TyrRS has an ELR motif that, like CXC-chemokinessuch as IL-8, is involved in many of its chemokine and angiogenicactivities. As in other ELR-containing cytokines, mutation of this motifinhibits mini-TyrRS binding to and stimulation of leukocytes andangiogenesis.

In addition, truncated forms of TrpRS have been demonstrated to haveanti-angiogenic properties. In normal human cells, there are two formsof TrpRS that can be detected: a major form consisting of thefull-length molecule (amino acid residues 1-471) and a minor truncatedform. The minor form is generated by the deletion of an amino-terminaldomain through alternative splicing of the pre-mRNA and is termedmini-TrpRS. The amino-terminus of miniTrpRS has been determined to bethe methionine residue at position 48 of the full-length TrpRS molecule.Alternatively, truncated TrpRS can be generated by proteolysis. Forexample, bovine TrpRS is highly expressed in the pancreas and issecreted into the pancreatic juice, thus resulting in the production ofa truncated TrpRS molecule. Additional studies indicate that mini-TrpRSinhibits VEGF-induced cell proliferation and migration (Wakasugi et al.,Proc. Natl. Acad. Sci. 99: 173-177 (2002)). In particular, a chick CAMassay shows that mini TrpRS blocks angiogenic activity of VEGF. Incontrast, the full-length TrpRS does not inhibit angiogenesis. Thus,removal of the first 48 amino acid residues exposes the anti-angiogenicactivity of TrpRS. Therefore, as with TyrRS, certain forms of TrpRSpossess activities other than the aminoacylation of tRNA.

Given these observations of non-canonical and therapeutically relevantactivities associated with alternative forms of TyrRS and TrpRS, thereis a need to identify biologically relevant forms of otheraminoacyl-tRNA synthetase proteins in order to exploit the fulltherapeutic potential of this family of proteins. Accordingly, thepresent invention addresses these needs and offers other relatedadvantages.

SUMMARY OF THE INVENTION

The present invention stems from the discovery that glycyl-tRNAsynthetase (GlyRS) and certain polypeptides derived from GlyRS possessnon-canonical biological activities of therapeutic relevance. Therefore,according to one aspect, the present invention provides isolated GlyRSpolypeptides having at least one non-canonical biological activity, aswell as active fragments and variants thereof which substantially retainsaid non-canonical activity. “Non-canonical” activity,” as used herein,refers generally to an activity possessed by a GlyRS polypeptide of theinvention that is other than the addition of glycine onto a tRNA^(Gly)molecule. As detailed herein, in certain embodiments, a non-canonicalbiological activity exhibited by a GlyRS polypeptide of the inventionmay include, but is not limited to, modulation of cell proliferation,modulation of apoptosis, modulation of cell migration, modulation ofcell signaling and/or modulation of cytokine production and/orsecretion. In more specific embodiments, the activity includesmodulation of Akt-mediated cell signaling, modulation of Erk1/2-mediatedcell signaling and modulation of GPCR-mediated cell signaling,modulation of endothelial cell tube formation, and modulation of cellbinding. In other specific embodiments, the activity includes modulationof CD71 and/or CD80. In yet other specific embodiments, the activityincludes modulation of cytokine production and/or release, wherein thecytokine is selected from the group consisting of TNF-α, IL1-β, IL-6,IL-8, IL-10, IL-12p40, MIP1-α, MIP-1β, GRO-α, MCP-1 and IL-1ra.

In certain embodiments, the GlyRS polypeptide of the invention is acontiguous fragment of a full length mammalian GlyRS protein. In a morespecific embodiment, the GlyRS polypeptide is a contiguous fragment ofthe human GlyRS protein sequence set forth in SEQ ID NO: 1.Illustratively, the fragments may be of essentially any length, andfurther provided they retain at least one non-canonical biologicalactivity of interest. In certain illustrative embodiments, a GlyRSpolypeptide of the invention will range in size from about 50-100,50-200, 50-300. 50-400, 50-500 or 50-600 amino acids in length. In otherembodiments, the GlyRS polypeptide of the invention will range in sizefrom about 100-200, 100-300, 100-400, 100-500 or 100-600 amino acids inlength. In still other illustrative embodiments, the GlyRS polypeptideof the invention will range in size from about 200-300, 200-400, 200-500or 200-600 amino acids in length.

In further embodiments of the invention, a GlyRS polypeptide comprisesan active variant (i.e., retains at least one non-canonical biologicalactivity of interest) of a fragment of a GlyRS protein sequence, such asthe human GlyRS protein sequence set forth in SEQ ID NO: 1. In a morespecific embodiment, the active variant is a polypeptide having at least70%, 80%, 90%, 95% or 99% identity along its length to a humanglycyl-tRNA synthetase sequence set forth in SEQ ID NO: 1.

Other embodiments of the invention provide GlyRS splice variants andmutants, whether naturally or non-naturally occurring, that possess oneor more non-canonical activities as described herein.

In more specific embodiments of the invention, a GlyRS polypeptidecomprises a fragment of a GlyRS sequence (e.g., SEQ ID NO: 1),consisting essentially of amino acid residues 57-685, 214-685, 239-685,311-685, 439-685, 511-658, 214-438, 367-438, 214-420, 214-338, 85-127 or25-56, 1-213, 1-61, 85-214, 333-685, 128-685, 265-685 or 483-685, or anactive fragment or variant thereof that substantially retains at leastone non-canonical biological activity of interest.

In other specific embodiments, the GlyRS polypeptide is not apolypeptide as set forth in any one of NCBI #CR594947, U09587 and/orU09510.

According to another aspect of the invention, there are provided fusionproteins comprising at least one GlyRS polypeptide as described hereinand a heterologous fusion partner.

According to another aspect of the invention, there are providedisolated polynucleotides encoding the polypeptides and fusion proteinsas described herein, as well as expression vectors comprising suchpolynucleotides, and host cell comprising such expression vectors.

According to yet another aspect of the invention, there are providedcompositions, e.g., pharmaceutical compositions, comprisingphysiologically acceptable carriers and at least one of the isolatedpolypeptides, fusion proteins, antibodies, isolated polynucleotides,expression vectors, host cells, etc., of the invention, as describedherein.

Also provided by the present invention, in other aspects, are methodsfor modulating a cellular activity by contacting a cell or tissue with acomposition of the invention, as described herein, wherein the cellularactivity to be modulated is selected from the group consisting of cellproliferation, modulation of apoptosis, modulation of cell migration,modulation of cell signaling and/or modulation of cytokine productionand/or secretion. In more specific embodiments, the cellular activity isselected from the group consisting of modulation of Akt-mediated cellsignaling, modulation of Erk1/2-mediated cell signaling, modulation ofGPCR-mediated cell signaling, modulation of endothelial cell tubeformation, and modulation of cell binding. In other specificembodiments, the cellular activity is selected from the group consistingof modulation of CD71 and/or CD80. In yet other specific embodiments,the cellular activity is selected from the group consisting ofmodulation of cytokine production and/or release, for example, whereinthe cytokine is selected from the group consisting of TNF-α, IL1-β,IL-6, IL-8, IL-10, IL-12p40, MIP1-α, MIP-1β, GRO-α, MCP-1 and IL-1ra.

In other aspects, the present invention provides methods for treating adisease, disorder or other condition in a subject in need thereof byadministering a composition according to the present invention. By wayof illustration, such diseases, disorders or conditions may include, butare not limited to, cancer, inflammatory disease, immune disease(including autoimmune disease), diseases associated with abnormalhematopoietic activity, diseases where neurogenesis or neuroprotectionis desired, metabolic disorders and/or conditions associated withabnormal angiogenesis.

In still other aspects, the polynucleotides, polypeptides, antibodiesand/or other compositions of the present invention may be used inessentially any type of screening assay known and available in the art.For example, compositions of the invention (e.g., polypeptides,polynucleotides and/or antibodies) may be used in conjunction with knownscreening methodologies in order to identify suitable cell types and/ordisease conditions amenable to treatment according to the presentinvention. In other examples, compositions of the invention (e.g.,polypeptides, polynucleotides and/or antibodies) may be used inconjunction with known screening methodologies in order to identifyagonists, antagonists, binding partners, competitive inhibitors,cellular effectors, and the like, that mediate or modulate, eitherdirectly or indirectly, the non-canonical activities of the compositionsherein. For example, in a particular embodiment, a screening method isprovided for identifying test compounds as inhibitors, or alternatively,potentiators, of a non-canonical activity or of an interaction between acomposition of the invention and one or more of its binding partners,cellular effectors and/or cell types subject to modulation. This mayinclude, for example, steps of forming a reaction mixture including: (i)a composition of the invention, (ii) a binding partner, cellulareffector and/or cell type known to be bound and/or modulated by saidcomposition, and (iii) a test compound; and detecting whether bindingand/or modulation in the presence of the test compound in increased ordecreased. A statistically significant change (potentiation orinhibition) in activity or modulation in the presence of the testcompound, relative to the effect in the absence of the test compound,indicates a potential agonist (mimetic or potentiator) or antagonist(inhibitor) of binding and/or activity.

BRIEF DESCRIPTION OF SEQUENCE IDENTIFIERS

SEQ ID NO: 1 is the full length amino acid sequence of human cytoplasmicglycyl-tRNA synthetase (GlyRS).

SEQ ID NO: 2 is a nucleic acid sequence encoding the GlyRS polypeptideof SEQ ID NO: 1.

SEQ ID NOs: 3-9 represent illustrative peptide sequences analyzed indetermining GlyRS fragment boundaries (see Example 4 & Table 1)

SEQ ID NOs: 10 and 11 are GlyRS sequences used in identifying fragmentssecreted from LPS-treated mouse macrophage cells (see Example 12 & FIG.16)

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D show the domain structure and amino acid sequence of theGlyRS protein (FIG. 1B; SEQ ID NO: 1), and illustrate the SDS-PAGEseparation of fragments of GlyRS generated by controlled proteolysis ofthe full-length GlyRS protein with human neutrophil elastase.

FIGS. 2A-2B demonstrate the activation of Akt and Gi-GPCRs,respectively, in endothelial cells treated with GlyRS fragments of theinvention.

FIG. 3 demonstrates the activation of Erk1/2 (mitogen-activated proteinkinase Erk1 and Erk2) in monocyte cells treated with GlyRS fragments ofthe invention.

FIG. 4A depicts an overview of the process for analyzing GlyRS peptides(e.g., SEQ ID NO: 9) for determining GlyRS fragment boundaries. FIG. 4Bshows the structure of the GlyRS fragment G6 corresponding to aminoacids 214-438, within the crystal structure of full length human GlyRSdimer.

FIG. 5 shows that the GlyRS fragment G6, corresponding to amino acids214-438, binds to endothelial cells.

FIG. 6 demonstrates that GlyRS fragment G6 modulates migration ofmonocyte cells. FIG. 6 (inset) demonstrates that GlyRS fragment G6signals through select chemokine receptors.

FIG. 7A shows representative stainings of CD41+ colonies. FIG. 7B showsthe results of quantitation of small, medium and large colonies, anddemonstrates that GlyRS fragment G6 affects colony formation ofmegakaryocyte progenitor cells.

FIG. 8 shows upregulation of the CD71 proliferation marker in G6-3treated monocytes after staining with anti-CD71-FITC antibody andanalysis by flow cytometry.

FIG. 9 shows upregulation of the CD80 activation marker in G6-3 treatedmonocytes after staining with anti-CD80-FITC antibody and analysis byflow cytometry.

FIG. 10 shows that GlyRS and the G6 fragments stimulate secretion ofnumerous cytokines, including IL1-β, IL-6, IL-8, IL-10, IL-12p40,MIP1-α, MIP-1β, GRO-α, MCP-1, and IL-1ra.

FIGS. 11A and 11B show that GlyRS fragments G6 and G6-3 induce migrationof mouse leukaemic macrophage cells.

FIG. 12 shows that GlyRS fragment G6 induces migration of HL-60promyelocytic leukemia cells.

FIG. 13 shows that GlyRS was detected in both the cell lysate and mediaof mouse macropphages, indicating endogenous secretion of full-lengthGlyRS.

FIG. 14 shows that upon LPS treatment of mouse macrophages, specificfragments of GlyRS can be found in the secreted media but not in thecell lysate, indicating the creation and secretion of GlyRS fragments.

FIG. 15 shows the results of LC/MS/MS analysis to identify the portionsof the full-length protein from which the fragments were generatedfollowing LPS treatment of mouse macrophages.

FIG. 16A shows sequence information for supernatant band 9, a GRSfragment having a molecular weight of ˜45-50 kd, with relevant peptidesequences shown in bold. FIG. 16B shows sequence information forsupernatant band 18, a GRS fragment having a molecular weight of ˜15 kd,with relevant peptide sequences shown in bold.

DETAILED DESCRIPTION OF THE INVENTION

The practice of the present invention will employ, unless indicatedspecifically to the contrary, conventional methods of molecular biologyand recombinant DNA techniques within the skill of the art, many ofwhich are described below for the purpose of illustration. Suchtechniques are explained fully in the literature. See, e.g., Sambrook,et al., Molecular Cloning: A Laboratory Manual (2nd Edition, 1989);Maniatis et al., Molecular Cloning: A Laboratory Manual (1982); DNACloning: A Practical Approach, vol. I & II (D. Glover, ed.);Oligonucleotide Synthesis (N. Gait, ed., 1984); Nucleic AcidHybridization (B. Hames & S. Higgins, eds., 1985); Transcription andTranslation (B. Hames & S. Higgins, eds., 1984); Animal Cell Culture (R.Freshney, ed., 1986); A Practical Guide to Molecular Cloning (B. Perbal,ed., 1984).

All publications, patents and patent applications cited herein arehereby incorporated by reference in their entirety.

As used in this specification and the appended claims, the singularforms “a,” “an” and “the” include plural references unless the contentclearly dictates otherwise.

As used herein, the terms “polypeptide” and “protein” are used accordingto conventional meaning, i.e., as a sequence of amino acids.Polypeptides are not limited to a specific length, but, in the contextof the present invention, typically represent a fragment of a fulllength protein, and may include post-translational modifications, forexample, glycosylations, acetylations, phosphorylations and the like, aswell as other modifications known in the art, both naturally occurringand non-naturally occurring. Polypeptides and proteins of the inventionmay be prepared using any of a variety of well known recombinant and/orsynthetic techniques, illustrative examples of which are furtherdiscussed below.

Glycyl-tRNA Synthetase Polypeptides

The present invention relates generally to isolated GlyRS polypeptides,polynucleotides encoding such polypeptides, binding agents that bindsuch polypeptides, analogs, variants and fragments of such polypeptides,etc., as well as compositions and methods of using any of the foregoing.

Therefore, according to one aspect of the invention, there are providedGlyRS polypeptides having non-canonical activities of therapeuticrelevance, as well as compositions comprising same. In certainembodiments, the GlyRS polypeptide is a truncated form of a GlyRSprotein. A “truncated” GlyRS, as used herein, refers to a glycyl-tRNAsynthetase protein which is shorter than its corresponding full lengthGlyRS protein, for example, due to removal of amino acids from its N-and/or C-terminal ends. The extent of the truncation, that is, thenumber of N- and/or C-terminal amino acid residues removed from a fulllength GlyRS protein can vary considerably while still providing desiredcellular effects when administered to a cell, tissue or subject, asdescribed herein. In certain embodiments, at least about 5, 10, 15, 20,25, 50, 75, 100, 150, 200, 250, 300, 350 amino acids, or more, includingall intermediate lengths, are truncated from the N- and/or C-terminus ofa full length GlyRS protein. Intermediate lengths are intended toinclude all integers there between, for example, 6, 7, 8, etc., 51, 52,53, etc., 201, 202, 203, etc.

In certain illustrative embodiments, truncated GlyRS polypeptides may beproduced using any of a variety of proteolytic enzymes using techniquesknown and available in the art. Illustrative proteases include, forexample, achromopeptidase, aminopeptidase, ancrod, angiotensinconverting enzyme, bromelain, calpain, calpain I, calpain II,carboxypeptidase A, carboxypeptidase B, carboxypeptidase G,carboxypeptidase P, carboxypeptidase W, carboxypeptidase Y, caspase 1,caspase 2, caspase 3, caspase 4, caspase 5, caspase 6, caspase 7,caspase 8, caspase 9, caspase 10, caspase 11, caspase 12, caspase 13,cathepsin B, cathepsin C, cathepsin D, cathepsin E, cathepsin G,cathepsin H, cathepsin L, chymopapain, chymase, chymotrypsin,clostripain, collagenase, complement C1r, complement C1s, complementFactor D, complement factor I, cucumisin, dipeptidyl peptidase IV,elastase (leukocyte), elastase (pancreatic), endoproteinase Arg-C,endoproteinase Asp-N, endoproteinase Glu-C, endoproteinase Lys-C,enterokinase, factor Xa, ficin, furin, granzyme A, granzyme B, HIVProtease, IGase, kallikrein tissue, leucine aminopeptidase (general),leucine aminopeptidase (cytosol), leucine aminopeptidase (microsomal),matrix metalloprotease, methionine aminopeptidase, neutrase, papain,pepsin, plasmin, prolidase, pronase E, prostate specific antigen,protease alkalophilic from Streptomyces griseus, protease fromAspergillus, protease from Aspergillus saitoi, protease from Aspergillussojae, protease (B. licheniformis) (alkaline or alcalase), protease fromBacillus polymyxa, protease from Bacillus sp, protease from Rhizopussp., protease S, proteasomes, proteinase from Aspergillus oryzae,proteinase 3, proteinase A, proteinase K, protein C, pyroglutamateaminopeptidase, rennin, rennin, streptokinase, subtilisin, thermolysin,thrombin, tissue plasminogen activator, trypsin, tryptase and urokinase.

In certain embodiments, the present invention provides variants of theGlyRS polypeptides described herein. Polypeptide variants encompassed bycertain illustrative embodiments of the present invention will typicallyexhibit at least about 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% identity (determined as described below), alongtheir lengths, to the corresponding region of a wild-type GlyRS protein,such as SEQ ID NO: 1.

A polypeptide variant may differ from a naturally occurring GlyRSpolypeptide in one or more substitutions, deletions, additions and/orinsertions. Such variants may be naturally occurring or may besynthetically generated, for example, by modifying one or more of theabove polypeptide sequences of the invention and evaluating theirbiological activity as described herein using any of a number oftechniques well known in the art.

In other illustrative embodiments, the GlyRS variant may be a splicevariant, whether naturally or non-naturally occurring, wherein thesplice variant possesses at least one non-canonical activity, e.g., asdescribed herein.

In other illustrative embodiments, the variant contains one or morepoint mutations relative to a wild type GlyRS polypeptide sequence,whether naturally or non-naturally occurring, wherein the variantpolypeptide possesses at least one non-canonical activity, e.g., asdescribed herein.

In certain embodiments, a variant will contain conservativesubstitutions. A “conservative substitution” is one in which an aminoacid is substituted for another amino acid that has similar properties,such that one skilled in the art would expect the secondary structureand hydropathic nature of the polypeptide to be substantially unchanged.Modifications may be made in the structure of the polynucleotides andpolypeptides of the present invention and still obtain a functionalmolecule that encodes a variant or derivative polypeptide with desirablecharacteristics. When it is desired to alter the amino acid sequence ofa polypeptide to create an equivalent, or even an improved, variant of aGlyRS polypeptide of the invention, one skilled in the art, for example,can change one or more of the codons of the encoding DNA sequenceaccording to Table 1.

For example, certain amino acids may be substituted for other aminoacids in a protein structure without appreciable loss of interactivebinding capacity with structures such as, for example, receptors,antigen-binding regions of antibodies or binding sites on a substratemolecule. Since it is the interactive capacity and nature of a proteinthat generally defines that protein's biological functional activity,certain amino acid sequence substitutions can be made in a proteinsequence, and, of course, its underlying DNA coding sequence, andnevertheless obtain a protein with like properties. It is thuscontemplated that various changes may be made in the polypeptidesequences of the disclosed compositions, or corresponding DNA sequenceswhich encode said polypeptides without appreciable loss of their desiredutility or activity.

TABLE 1 Amino Acids Codons Alanine Ala A GCA GCC GCG GCU Cysteine Cys CUGC UGU Aspartic acid Asp D GAC GAU Glutamic acid Glu E GAA GAGPhenylalanine Phe F UUC UUU Glycine Gly G GGA GGC GGG GGU Histidine HisH CAC CAU Isoleucine Ile I AUA AUC AUU Lysine Lys K AAA AAG Leucine LeuL UUA UUG CUA CUC CUG CUU Methionine Met M AUG Asparagine Asn N AAC AAUProline Pro P CCA CCC CCG CCU Glutamine Gln Q CAA CAG Arginine Arg R AGAAGG CGA CGC CGG CGU Serine Ser S AGC AGU UCA UCC UCG UCU Threonine Thr TACA ACC ACG ACU Valine Val V GUA GUC GUG GUU Tryptophan Trp W UGGTyrosine Tyr Y UAC UAU

In making such changes, the hydropathic index of amino acids may also beconsidered. The importance of the hydropathic amino acid index inconferring interactive biologic function on a protein is generallyunderstood in the art (Kyte and Doolittle, 1982, incorporated herein byreference). For example, it is known that the relative hydropathiccharacter of the amino acid contributes to the secondary structure ofthe resultant protein, which in turn defines the interaction of theprotein with other molecules, for example, enzymes, substrates,receptors, DNA, antibodies, antigens, and the like. Each amino acid hasbeen assigned a hydropathic index on the basis of its hydrophobicity andcharge characteristics (Kyte and Doolittle, 1982). These values are:isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8);cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine(−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine(−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine(−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine(−4.5).

It is known in the art that certain amino acids may be substituted byother amino acids having a similar hydropathic index or score and stillresult in a protein with similar biological activity, i.e. still obtaina biological functionally equivalent protein. In making such changes,the substitution of amino acids whose hydropathic indices are within ±2is preferred, those within ±1 are particularly preferred, and thosewithin ±0.5 are even more particularly preferred.

It is also understood in the art that the substitution of like aminoacids can be made effectively on the basis of hydrophilicity. Asdetailed in U.S. Pat. No. 4,554,101, the following hydrophilicity valueshave been assigned to amino acid residues: arginine (+3.0); lysine(+3.0); aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3);asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4);proline (−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0);methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8);tyrosine (−2.3); phenylalanine (−2.5); tryptophan (−3.4). It isunderstood that an amino acid can be substituted for another having asimilar hydrophilicity value and still obtain a biologically equivalentprotein. In such changes, the substitution of amino acids whosehydrophilicity values are within ±2 is preferred, those within ±1 areparticularly preferred, and those within ±0.5 are even more particularlypreferred.

As outlined above, amino acid substitutions may be based on the relativesimilarity of the amino acid side-chain substituents, for example, theirhydrophobicity, hydrophilicity, charge, size, and the like. Exemplarysubstitutions that take various of the foregoing characteristics intoconsideration are well known to those of skill in the art and include:arginine and lysine; glutamate and aspartate; serine and threonine;glutamine and asparagine; and valine, leucine and isoleucine.

Amino acid substitutions may further be made on the basis of similarityin polarity, charge, solubility, hydrophobicity, hydrophilicity and/orthe amphipathic nature of the residues. For example, negatively chargedamino acids include aspartic acid and glutamic acid; positively chargedamino acids include lysine and arginine; and amino acids with unchargedpolar head groups having similar hydrophilicity values include leucine,isoleucine and valine; glycine and alanine; asparagine and glutamine;and serine, threonine, phenylalanine and tyrosine. Other groups of aminoacids that may represent conservative changes include: (1) ala, pro,gly, glu, asp, gln, asn, ser, thr; (2) cys, ser, tyr, thr; (3) val, ile,leu, met, ala, phe; (4) lys, arg, his; and (5) phe, tyr, trp, his. Avariant may also, or alternatively, contain non-conservative changes. Ina preferred embodiment, variant polypeptides differ from a nativesequence by substitution, deletion or addition of five amino acids orfewer. Variants may also (or alternatively) be modified by, for example,the deletion or addition of amino acids that have minimal influence onsecondary structure and hydropathic nature of the polypeptide.

Polypeptides may comprise a signal (or leader) sequence at theN-terminal end of the protein, which co-translationally orpost-translationally directs transfer of the protein. The polypeptidemay also be conjugated to a linker or other sequence for ease ofsynthesis, purification or identification of the polypeptide (e.g.,poly-His), or to enhance binding of the polypeptide to a solid support.For example, a polypeptide may be conjugated to an immunoglobulin Fcregion.

When comparing polypeptide sequences, two sequences are said to be“identical” if the sequence of amino acids in the two sequences is thesame when aligned for maximum correspondence, as described below.Comparisons between two sequences are typically performed by comparingthe sequences over a comparison window to identify and compare localregions of sequence similarity. A “comparison window” as used herein,refers to a segment of at least about 20 contiguous positions, usually30 to about 75, 40 to about 50, in which a sequence may be compared to areference sequence of the same number of contiguous positions after thetwo sequences are optimally aligned.

Optimal alignment of sequences for comparison may be conducted, forexample, using the Megalign program in the Lasergene suite ofbioinformatics software (DNASTAR, Inc., Madison, Wis.), using defaultparameters. This program embodies several alignment schemes described inthe following references: Dayhoff, M. O. (1978) A model of evolutionarychange in proteins—Matrices for detecting distant relationships. InDayhoff, M. O. (ed.) Atlas of Protein Sequence and Structure, NationalBiomedical Research Foundation, Washington D.C. Vol. 5, Suppl. 3, pp.345-358; Hein J. (1990) Unified Approach to Alignment and Phylogenes pp.626-645 Methods in Enzymology vol. 183, Academic Press, Inc., San Diego,Calif.; Higgins, D. G. and Sharp, P. M. (1989) CABIOS 5:151-153; Myers,E. W. and Muller W. (1988) CABIOS 4:11-17; Robinson, E. D. (1971) Comb.Theor 11:105; Santou, N. Nes, M. (1987) Mol. Biol. Evol. 4:406-425;Sneath, P. H. A. and Sokal, R. R. (1973) Numerical Taxonomy—thePrinciples and Practice of Numerical Taxonomy, Freeman Press, SanFrancisco, Calif.; Wilbur, W. J. and Lipman, D. J. (1983) Proc. Nat'lAcad., Sci. USA 80:726-730.

Alternatively, optimal alignment of sequences for comparison may beconducted by the local identity algorithm of Smith and Waterman (1981)Add. APL. Math 2:482, by the identity alignment algorithm of Needlemanand Wunsch (1970) J. Mol. Biol. 48:443, by the search for similaritymethods of Pearson and Lipman (1988) Proc. Nat'l Acad. Sci. USA 85:2444, by computerized implementations of these algorithms (GAP, BESTFIT,BLAST, FASTA, and TFASTA in the Wisconsin Genetics Software Package,Genetics Computer Group (GCG), 575 Science Dr., Madison, Wis.), or byinspection.

Examples of algorithms that are suitable for determining percentsequence identity and sequence similarity are the BLAST and BLAST 2.0algorithms, which are described in Altschul et al. (1977) Nucl. AcidsRes. 25:3389-3402 and Altschul et al. (1990) J. Mol. Biol. 215:403-410,respectively. BLAST and BLAST 2.0 can be used, for example with theparameters described herein, to determine percent sequence identity forthe polynucleotides and polypeptides of the invention. Software forperforming BLAST analyses is publicly available through the NationalCenter for Biotechnology Information. For amino acid sequences, ascoring matrix can be used to calculate the cumulative score. Extensionof the word hits in each direction are halted when: the cumulativealignment score falls off by the quantity X from its maximum achievedvalue; the cumulative score goes to zero or below, due to theaccumulation of one or more negative-scoring residue alignments; or theend of either sequence is reached. The BLAST algorithm parameters W, Tand X determine the sensitivity and speed of the alignment.

In one illustrative approach, the “percentage of sequence identity” isdetermined by comparing two optimally aligned sequences over a window ofcomparison of at least 20 positions, wherein the portion of thepolypeptide sequence in the comparison window may comprise additions ordeletions (i.e., gaps) of 20 percent or less, usually 5 to 15 percent,or 10 to 12 percent, as compared to the reference sequences (which doesnot comprise additions or deletions) for optimal alignment of the twosequences. The percentage is calculated by determining the number ofpositions at which the identical amino acid residue occurs in bothsequences to yield the number of matched positions, dividing the numberof matched positions by the total number of positions in the referencesequence (i.e., the window size) and multiplying the results by 100 toyield the percentage of sequence identity.

In certain embodiments of the invention, there are provided fusionpolypeptides, and polynucleotides encoding fusion polypeptides. Fusionpolypeptides refer to polypeptides of the invention that have beencovalently linked, either directly or indirectly via an amino acidlinker, to one or more heterologous polypeptide sequences (fusionpartners). The polypeptides forming the fusion protein are typicallylinked C-terminus to N-terminus, although they can also be linkedC-terminus to C-terminus, N-terminus to N-terminus, or N-terminus toC-terminus. The polypeptides of the fusion protein can be in any order.

The fusion partner may be designed and included for essentially anydesired purpose provided they do not adversely effect the desiredactivity of the polypeptide. For example, in one embodiment, a fusionpartner comprises a sequence that assists in expressing the protein (anexpression enhancer) at higher yields than the native recombinantprotein. Other fusion partners may be selected so as to increase thesolubility of the protein or to enable the protein to be targeted todesired intracellular compartments. Still further fusion partnersinclude affinity tags, which facilitate purification of the protein.

Fusion proteins may generally be prepared using standard techniques. Forexample, DNA sequences encoding the polypeptide components of a desiredfusion may be assembled separately, and ligated into an appropriateexpression vector. The 3′ end of the DNA sequence encoding onepolypeptide component is ligated, with or without a peptide linker, tothe 5′ end of a DNA sequence encoding the second polypeptide componentso that the reading frames of the sequences are in phase. This permitstranslation into a single fusion protein that retains the biologicalactivity of both component polypeptides.

A peptide linker sequence may be employed to separate the first andsecond polypeptide components by a distance sufficient to ensure thateach polypeptide folds into its secondary and tertiary structures, ifdesired. Such a peptide linker sequence is incorporated into the fusionprotein using standard techniques well known in the art. Certain peptidelinker sequences may be chosen based on the following factors: (1) theirability to adopt a flexible extended conformation; (2) their inabilityto adopt a secondary structure that could interact with functionalepitopes on the first and second polypeptides; and (3) the lack ofhydrophobic or charged residues that might react with the polypeptidefunctional epitopes. Preferred peptide linker sequences contain Gly, Asnand Ser residues. Other near neutral amino acids, such as Thr and Alamay also be used in the linker sequence. Amino acid sequences which maybe usefully employed as linkers include those disclosed in Maratea etal., Gene 40:39 46 (1985); Murphy et al., Proc. Natl. Acad. Sci. USA83:8258 8262 (1986); U.S. Pat. Nos. 4,935,233 and 4,751,180. The linkersequence may generally be from 1 to about 50 amino acids in length.Linker sequences are not required when the first and second polypeptideshave non-essential N-terminal amino acid regions that can be used toseparate the functional domains and prevent steric interference.

The ligated DNA sequences are operably linked to suitabletranscriptional or translational regulatory elements. The regulatoryelements responsible for expression of DNA are located 5′ to the DNAsequence encoding the first polypeptides. Similarly, stop codonsrequired to end translation and transcription termination signals arepresent 3′ to the DNA sequence encoding the second polypeptide.

In general, polypeptides and fusion polypeptides (as well as theirencoding polynucleotides) are isolated. An “isolated” polypeptide orpolynucleotide is one that is removed from its original environment. Forexample, a naturally-occurring protein is isolated if it is separatedfrom some or all of the coexisting materials in the natural system.Preferably, such polypeptides are at least about 90% pure, morepreferably at least about 95% pure and most preferably at least about99% pure. A polynucleotide is considered to be isolated if, for example,it is cloned into a vector that is not a part of the naturalenvironment.

In still other embodiments, a GlyRS polypeptide of the invention may bepart of a dimer. Dimers may include, for example, homodimers between twoidentical GlyRS polypeptides, heterodimers between two different GlyRSpolypeptides (e.g., a full-length GlyRS polypeptide and a truncatedGlyRS polypeptide, or two different truncated GlyRS polypeptides),and/or heterodimers between a GlyRS polypeptide and a heterologouspolypeptide. The monomers and/or dimers may be soluble and may beisolated or purified to homogeneity. Certain heterodimers, such as thosebetween a GlyRS polypeptide and a heterologous polypeptide, may bebi-functional.

In other embodiments, a GlyRS polypeptide of the invention may be partof a multi-unit complex. A multi-unit complex of the present inventioncan include, for example, at least 2, 3, 4, or 5 or more monomers. Themonomers and/or multi-unit complexes may be soluble and may be isolatedor purified to homogeneity. Monomer units of a multi-unit complex may bedifferent, homologous, substantially homologous, or identical to oneanother. However, a multi-unit complex of the invention includes atleast one monomer comprising a GlyRS polypeptide as described herein or,in other embodiments, at least two or more GlyRS polypeptides, asdescribed herein.

Covalently linked monomers can be linked directly (by bonds) orindirectly (e.g., via a linker). For directly linking the polypeptidemonomers herein, it may be beneficial to modify the polypeptides hereinto enhance dimerization or multimerization. For example, one or moreamino acid residues of a GlyRS polypeptide may be modified by theaddition or substitution by one or more cysteines. Methods for creatingamino acid substitutions, such as cysteine substitutions, or othermodifications to facilitate linking, are well known to those skilled inthe art.

Certain embodiments of the present invention also contemplate the use ofmodified GlyRS polypeptides, including modifications that improvedesired characteristics of a GlyRS polypeptide, as described herein.Illustrative modifications of GlyRS polypeptides of the inventioninclude, but are not limited to, chemical and/or enzymaticderivatizations at one or more constituent amino acid, including sidechain modifications, backbone modifications, and N- and C-terminalmodifications including acetylation, hydroxylation, methylation,amidation, and the attachment of carbohydrate or lipid moieties,cofactors, and the like. Exemplary modifications also include pegylationof a GlyRS-polypeptide (see, e.g., Veronese and Harris, Advanced DrugDelivery Reviews 54: 453-456, 2002, herein incorporated by reference).

In certain aspects, chemoselective ligation technology may be utilizedto modify truncated GlyRS polypeptides of the invention, such as byattaching polymers in a site-specific and controlled manner. Suchtechnology typically relies on the incorporation of chemoselectiveanchors into the protein backbone by either chemical or recombinantmeans, and subsequent modification with a polymer carrying acomplementary linker. As a result, the assembly process and the covalentstructure of the resulting protein-polymer conjugate may be controlled,enabling the rational optimization of drug properties, such as efficacyand pharmacokinetic properties (see, e.g., Kochendoerfer, CurrentOpinion in Chemical Biology 9:555-560, 2005).

Polynucleotide Compositions

The present invention also provides isolated polynucleotides that encodethe GlyRS polypeptides of the invention, as well as compositionscomprising such polynucleotides.

As used herein, the terms “DNA” and “polynucleotide” and “nucleic acid”refer to a DNA molecule that has been isolated free of total genomic DNAof a particular species. Therefore, a DNA segment encoding a polypeptiderefers to a DNA segment that contains one or more coding sequences yetis substantially isolated away from, or purified free from, totalgenomic DNA of the species from which the DNA segment is obtained.Included within the terms “DNA segment” and “polynucleotide” are DNAsegments and smaller fragments of such segments, and also recombinantvectors, including, for example, plasmids, cosmids, phagemids, phage,viruses, and the like.

As will be understood by those skilled in the art, the polynucleotidesequences of this invention can include genomic sequences, extra-genomicand plasmid-encoded sequences and smaller engineered gene segments thatexpress, or may be adapted to express, proteins, polypeptides, peptidesand the like. Such segments may be naturally isolated, or modifiedsynthetically by the hand of man.

As will be recognized by the skilled artisan, polynucleotides may besingle-stranded (coding or antisense) or double-stranded, and may be DNA(genomic, cDNA or synthetic) or RNA molecules. Additional coding ornon-coding sequences may, but need not, be present within apolynucleotide of the present invention, and a polynucleotide may, butneed not, be linked to other molecules and/or support materials.

Polynucleotides may comprise a native sequence (i.e., an endogenoussequence that encodes a GlyRS or a portion thereof) or may comprise avariant, or a biological functional equivalent of such a sequence.Polynucleotide variants may contain one or more substitutions,additions, deletions and/or insertions, as further described below,preferably such that the desired activity of the encoded polypeptide isnot substantially diminished relative to the unmodified polypeptide. Theeffect on the activity of the encoded polypeptide may generally beassessed as described herein.

In additional embodiments, the present invention provides isolatedpolynucleotides comprising various lengths of contiguous stretches ofsequence identical to or complementary to a glycyl-tRNA synthetase,wherein the isolated polynucleotides encode a GlyRS as described herein.

For example, polynucleotides are provided by this invention that encodeat least about 5, 10, 15, 20, 25, 50, 75, 100, 150, 200, 250, 300, 350,400, 450 or 500, or more, contiguous amino acid residues of a GlyRSpolypeptide of the invention, as well as all intermediate lengths. Itwill be readily understood that “intermediate lengths”, in this context,means any length between the quoted values, such as 101, 102, 103, etc.;151, 152, 153, etc.; 201, 202, 203, etc.

In other embodiments, the present invention is directed topolynucleotides that are capable of hybridizing under moderatelystringent conditions to a polynucleotide sequence provided herein, or afragment thereof, or a complementary sequence thereof. Hybridizationtechniques are well known in the art of molecular biology. For purposesof illustration, suitable moderately stringent conditions for testingthe hybridization of a polynucleotide of this invention with otherpolynucleotides include prewashing in a solution of 5×SSC, 0.5% SDS, 1.0mM EDTA (pH 8.0); hybridizing at 50° C.-65° C., 5×SSC, overnight;followed by washing twice at 65° C. for 20 minutes with each of 2×, 0.5×and 0.2×SSC containing 0.1% SDS.

The polynucleotides of the present invention, regardless of the lengthof the coding sequence itself, may be combined with other DNA sequences,such as promoters, polyadenylation signals, additional restrictionenzyme sites, multiple cloning sites, other coding segments, and thelike, such that their overall length may vary considerably. It istherefore contemplated that a polynucleotide fragment of almost anylength may be employed, with the total length preferably being limitedby the ease of preparation and use in the intended recombinant DNAprotocol.

Moreover, it will be appreciated by those of ordinary skill in the artthat, as a result of the degeneracy of the genetic code, there are manynucleotide sequences that encode a polypeptide as described herein. Someof these polynucleotides bear minimal homology to the nucleotidesequence of any native gene. Nonetheless, polynucleotides that vary dueto differences in codon usage are specifically contemplated by thepresent invention, for example polynucleotides that are optimized forhuman and/or primate codon selection. Further, alleles of the genescomprising the polynucleotide sequences provided herein are within thescope of the present invention. Alleles are endogenous genes that arealtered as a result of one or more mutations, such as deletions,additions and/or substitutions of nucleotides. The resulting mRNA andprotein may, but need not, have an altered structure or function.Alleles may be identified using standard techniques (such ashybridization, amplification and/or database sequence comparison).

Polynucleotides and fusions thereof may be prepared, manipulated and/orexpressed using any of a variety of well established techniques knownand available in the art. For example, polynucleotide sequences whichencode polypeptides of the invention, or fusion proteins or functionalequivalents thereof, may be used in recombinant DNA molecules to directexpression of a GlyRS polypeptide in appropriate host cells. Due to theinherent degeneracy of the genetic code, other DNA sequences that encodesubstantially the same or a functionally equivalent amino acid sequencemay be produced and these sequences may be used to clone and express agiven polypeptide.

As will be understood by those of skill in the art, it may beadvantageous in some instances to produce polypeptide-encodingnucleotide sequences possessing non-naturally occurring codons. Forexample, codons preferred by a particular prokaryotic or eukaryotic hostcan be selected to increase the rate of protein expression or to producea recombinant RNA transcript having desirable properties, such as ahalf-life which is longer than that of a transcript generated from thenaturally occurring sequence.

Moreover, the polynucleotide sequences of the present invention can beengineered using methods generally known in the art in order to alterpolypeptide encoding sequences for a variety of reasons, including butnot limited to, alterations which modify the cloning, processing,expression and/or activity of the gene product.

In order to express a desired polypeptide, a nucleotide sequenceencoding the polypeptide, or a functional equivalent, may be insertedinto appropriate expression vector, i.e., a vector which contains thenecessary elements for the transcription and translation of the insertedcoding sequence. Methods which are well known to those skilled in theart may be used to construct expression vectors containing sequencesencoding a polypeptide of interest and appropriate transcriptional andtranslational control elements. These methods include in vitrorecombinant DNA techniques, synthetic techniques, and in vivo geneticrecombination. Such techniques are described in Sambrook et al.,Molecular Cloning, A Laboratory Manual (1989), and Ausubel et al.,Current Protocols in Molecular Biology (1989).

A variety of expression vector/host systems are known and may beutilized to contain and express polynucleotide sequences. These include,but are not limited to, microorganisms such as bacteria transformed withrecombinant bacteriophage, plasmid, or cosmid DNA expression vectors;yeast transformed with yeast expression vectors; insect cell systemsinfected with virus expression vectors (e.g., baculovirus); plant cellsystems transformed with virus expression vectors (e.g., cauliflowermosaic virus, CaMV; tobacco mosaic virus, TMV) or with bacterialexpression vectors (e.g., Ti or pBR322 plasmids); or animal cellsystems.

The “control elements” or “regulatory sequences” present in anexpression vector are those non-translated regions of thevector—enhancers, promoters, 5′ and 3′ untranslated regions—whichinteract with host cellular proteins to carry out transcription andtranslation. Such elements may vary in their strength and specificity.Depending on the vector system and host utilized, any number of suitabletranscription and translation elements, including constitutive andinducible promoters, may be used. For example, when cloning in bacterialsystems, inducible promoters such as the hybrid lacZ promoter of thePBLUESCRIPT phagemid (Stratagene, La Jolla, Calif.) or PSPORT1 plasmid(Gibco BRL, Gaithersburg, Md.) and the like may be used. In mammaliancell systems, promoters from mammalian genes or from mammalian virusesare generally preferred. If it is necessary to generate a cell line thatcontains multiple copies of the sequence encoding a polypeptide, vectorsbased on SV40 or EBV may be advantageously used with an appropriateselectable marker.

In bacterial systems, a number of expression vectors may be selecteddepending upon the use intended for the expressed polypeptide. Forexample, when large quantities are needed, vectors which direct highlevel expression of fusion proteins that are readily purified may beused. Such vectors include, but are not limited to, the multifunctionalE. coli cloning and expression vectors such as BLUESCRIPT (Stratagene),in which the sequence encoding the polypeptide of interest may beligated into the vector in frame with sequences for the amino-terminalMet and the subsequent 7 residues of β-galactosidase so that a hybridprotein is produced; pIN vectors (Van Heeke & Schuster, J. Biol. Chem.264:5503 5509 (1989)); and the like. pGEX Vectors (Promega, Madison,Wis.) may also be used to express foreign polypeptides as fusionproteins with glutathione S-transferase (GST). In general, such fusionproteins are soluble and can easily be purified from lysed cells byadsorption to glutathione-agarose beads followed by elution in thepresence of free glutathione. Proteins made in such systems may bedesigned to include heparin, thrombin, or factor XA protease cleavagesites so that the cloned polypeptide of interest can be released fromthe GST moiety at will.

In the yeast Saccharomyces cerevisiae, a number of vectors containingconstitutive or inducible promoters such as alpha factor, alcoholoxidase, and PGH may be used. For reviews, see Ausubel et al. (supra)and Grant et al., Methods Enzymol. 153:516-544 (1987).

In cases where plant expression vectors are used, the expression ofsequences encoding polypeptides may be driven by any of a number ofpromoters. For example, viral promoters such as the 35S and 19Spromoters of CaMV may be used alone or in combination with the omegaleader sequence from TMV (Takamatsu, EMBO J. 6:307-311 (1987)).Alternatively, plant promoters such as the small subunit of RUBISCO orheat shock promoters may be used (Coruzzi et al., EMBO J. 3:1671-1680(1984); Broglie et al., Science 224:838-843 (1984); and Winter et al.,Results Probl. Cell Differ. 17:85-105 (1991)). These constructs can beintroduced into plant cells by direct DNA transformation orpathogen-mediated transfection. Such techniques are described in anumber of generally available reviews (see, e.g., Hobbs in McGraw Hill,Yearbook of Science and Technology, pp. 191-196 (1992)).

An insect system may also be used to express a polypeptide of interest.For example, in one such system, Autographa californica nuclearpolyhedrosis virus (AcNPV) is used as a vector to express foreign genesin Spodoptera frugiperda cells or in Trichoplusia larvae. The sequencesencoding the polypeptide may be cloned into a non-essential region ofthe virus, such as the polyhedrin gene, and placed under control of thepolyhedrin promoter. Successful insertion of the polypeptide-encodingsequence will render the polyhedrin gene inactive and producerecombinant virus lacking coat protein. The recombinant viruses may thenbe used to infect, for example, S. frugiperda cells or Trichoplusialarvae in which the polypeptide of interest may be expressed (Engelhardet al., Proc. Natl. Acad. Sci. U.S.A. 91:3224-3227 (1994)).

In mammalian host cells, a number of viral-based expression systems aregenerally available. For example, in cases where an adenovirus is usedas an expression vector, sequences encoding a polypeptide of interestmay be ligated into an adenovirus transcription/translation complexconsisting of the late promoter and tripartite leader sequence.Insertion in a non-essential E1 or E3 region of the viral genome may beused to obtain a viable virus which is capable of expressing thepolypeptide in infected host cells (Logan & Shenk, Proc. Natl. Acad.Sci. U.S.A. 81:3655-3659 (1984)). In addition, transcription enhancers,such as the Rous sarcoma virus (RSV) enhancer, may be used to increaseexpression in mammalian host cells.

Specific initiation signals may also be used to achieve more efficienttranslation of sequences encoding a polypeptide of interest. Suchsignals include the ATG initiation codon and adjacent sequences. Incases where sequences encoding the polypeptide, its initiation codon,and upstream sequences are inserted into the appropriate expressionvector, no additional transcriptional or translational control signalsmay be needed. However, in cases where only coding sequence, or aportion thereof, is inserted, exogenous translational control signalsincluding the ATG initiation codon should be provided. Furthermore, theinitiation codon should be in the correct reading frame to ensuretranslation of the entire insert. Exogenous translational elements andinitiation codons may be of various origins, both natural and synthetic.The efficiency of expression may be enhanced by the inclusion ofenhancers which are appropriate for the particular cell system which isused, such as those described in the literature (Scharf et al., ResultsProbl. Cell Differ. 20:125-162 (1994)).

In addition, a host cell strain may be chosen for its ability tomodulate the expression of the inserted sequences or to process theexpressed protein in the desired fashion. Such modifications of thepolypeptide include, but are not limited to, acetylation, carboxylation,glycosylation, phosphorylation, lipidation, and acylation.Post-translational processing which cleaves a “prepro” form of theprotein may also be used to facilitate correct insertion, folding and/orfunction. Different host cells such as CHO, HeLa, MDCK, HEK293, andW138, which have specific cellular machinery and characteristicmechanisms for such post-translational activities, may be chosen toensure the correct modification and processing of the foreign protein.

For long-term, high-yield production of recombinant proteins, stableexpression is generally preferred. For example, cell lines which stablyexpress a polynucleotide of interest may be transformed using expressionvectors which may contain viral origins of replication and/or endogenousexpression elements and a selectable marker gene on the same or on aseparate vector. Following the introduction of the vector, cells may beallowed to grow for 1-2 days in an enriched media before they areswitched to selective media. The purpose of the selectable marker is toconfer resistance to selection, and its presence allows growth andrecovery of cells which successfully express the introduced sequences.Resistant clones of stably transformed cells may be proliferated usingtissue culture techniques appropriate to the cell type.

Any number of selection systems may be used to recover transformed celllines. These include, but are not limited to, the herpes simplex virusthymidine kinase (Wigler et al., Cell 11:223-232 (1977)) and adeninephosphoribosyltransferase (Lowy et al., Cell 22:817-823 (1990)) geneswhich can be employed in tk- or aprt-cells, respectively. Also,antimetabolite, antibiotic or herbicide resistance can be used as thebasis for selection; for example, dhfr which confers resistance tomethotrexate (Wigler et al., Proc. Natl. Acad. Sci. U.S.A. 77:3567-70(1980)); npt, which confers resistance to the aminoglycosides, neomycinand G-418 (Colbere-Garapin et al., J. Mol. Biol. 150:1-14 (1981)); andals or pat, which confer resistance to chlorsulfuron and phosphinotricinacetyltransferase, respectively (Murry, supra). Additional selectablegenes have been described, for example, trpB, which allows cells toutilize indole in place of tryptophan, or hisD, which allows cells toutilize histinol in place of histidine (Hartman & Mulligan, Proc. Natl.Acad. Sci. U.S.A. 85:8047-51 (1988)). The use of visible markers hasgained popularity with such markers as anthocyanins, β-glucuronidase andits substrate GUS, and luciferase and its substrate luciferin, beingwidely used not only to identify transformants, but also to quantify theamount of transient or stable protein expression attributable to aspecific vector system (Rhodes et al., Methods Mol. Biol. 55:121-131(1995)).

A variety of protocols for detecting and measuring the expression ofpolynucleotide-encoded products, using either polyclonal or monoclonalantibodies specific for the product are known in the art. Examplesinclude enzyme-linked immunosorbent assay (ELISA), radioimmunoassay(RIA), and fluorescence activated cell sorting (FACS). These and otherassays are described, among other places, in Hampton et al., SerologicalMethods, a Laboratory Manual (1990) and Maddox et al., J. Exp. Med.158:1211-1216 (1983).

A wide variety of labels and conjugation techniques are known by thoseskilled in the art and may be used in various nucleic acid and aminoacid assays. Means for producing labeled hybridization or PCR probes fordetecting sequences related to polynucleotides include oligolabeling,nick translation, end-labeling or PCR amplification using a labelednucleotide. Alternatively, the sequences, or any portions thereof may becloned into a vector for the production of an mRNA probe. Such vectorsare known in the art, are commercially available, and may be used tosynthesize RNA probes in vitro by addition of an appropriate RNApolymerase such as T7, T3, or SP6 and labeled nucleotides. Theseprocedures may be conducted using a variety of commercially availablekits. Suitable reporter molecules or labels, which may be used includeradionuclides, enzymes, fluorescent, chemiluminescent, or chromogenicagents as well as substrates, cofactors, inhibitors, magnetic particles,and the like.

Host cells transformed with a polynucleotide sequence of interest may becultured under conditions suitable for the expression and recovery ofthe protein from cell culture. The protein produced by a recombinantcell may be secreted or contained intracellularly depending on thesequence and/or the vector used. As will be understood by those of skillin the art, expression vectors containing polynucleotides of theinvention may be designed to contain signal sequences which directsecretion of the encoded polypeptide through a prokaryotic or eukaryoticcell membrane. Other recombinant constructions may be used to joinsequences encoding a polypeptide of interest to nucleotide sequenceencoding a polypeptide domain which will facilitate purification ofsoluble proteins.

In addition to recombinant production methods, polypeptides of theinvention, and fragments thereof, may be produced by direct peptidesynthesis using solid-phase techniques (Merrifield, J. Am. Chem. Soc.85:2149-2154 (1963)). Protein synthesis may be performed using manualtechniques or by automation. Automated synthesis may be achieved, forexample, using Applied Biosystems 431A Peptide Synthesizer (PerkinElmer). Alternatively, various fragments may be chemically synthesizedseparately and combined using chemical methods to produce the fulllength molecule.

According to another aspect of the invention, polynucleotides encodingpolypeptides of the invention may be delivered to a subject in vivo,e.g., using gene therapy techniques. Gene therapy refers generally tothe transfer of heterologous nucleic acids to the certain cells, targetcells, of a mammal, particularly a human, with a disorder or conditionsfor which such therapy is sought. The nucleic acid is introduced intothe selected target cells in a manner such that the heterologous DNA isexpressed and a therapeutic product encoded thereby is produced.

Various viral vectors that can be utilized for gene therapy as taughtherein include adenovirus, herpes virus, vaccinia, adeno-associatedvirus (AAV), or, preferably, an RNA virus such as a retrovirus.Preferably, the retroviral vector is a derivative of a murine or avianretrovirus, or is a lentiviral vector. The preferred retroviral vectoris a lentiviral vector. Examples of retroviral vectors in which a singleforeign gene can be inserted include, but are not limited to: Moloneymurine leukemia virus (MoMuLV), Harvey murine sarcoma virus (HaMuSV),murine mammary tumor virus (MuMTV), SIV, BIV, HIV and Rous Sarcoma Virus(RSV). A number of additional retroviral vectors can incorporatemultiple genes. All of these vectors can transfer or incorporate a genefor a selectable marker so that transduced cells can be identified andgenerated. By inserting a zinc finger derived-DNA binding polypeptidesequence of interest into the viral vector, along with another gene thatencodes the ligand for a receptor on a specific target cell, forexample, the vector may be made target specific. Retroviral vectors canbe made target specific by inserting, for example, a polynucleotideencoding a protein (dimer). Illustrative targeting may be accomplishedby using an antibody to target the retroviral vector. Those of skill inthe art will know of, or can readily ascertain without undueexperimentation, specific polynucleotide sequences which can be insertedinto the retroviral genome to allow target specific delivery of theretroviral vector containing the zinc finger-nucleotide binding proteinpolynucleotide.

Since recombinant retroviruses are defective, they require assistance inorder to produce infectious vector particles. This assistance can beprovided, for example, by using helper cell lines that contain plasmidsencoding all of the structural genes of the retrovirus under the controlof regulatory sequences within the LTR. These plasmids are missing anucleotide sequence which enables the packaging mechanism to recognizean RNA transcript for encapsulation. Helper cell lines which havedeletions of the packaging signal include but are not limited to PSI.2,PA317 and PAl2, for example. These cell lines produce empty virions,since no genome is packaged. If a retroviral vector is introduced intosuch cells in which the packaging signal is intact, but the structuralgenes are replaced by other genes of interest, the vector can bepackaged and vector virion produced. The vector virions produced by thismethod can then be used to infect a tissue cell line, such as NIH 3T3cells, to produce large quantities of chimeric retroviral virions.

“Non-viral” delivery techniques for gene therapy can also be usedincluding, for example, DNA-ligand complexes, adenovirus-ligand-DNAcomplexes, direct injection of DNA, CaPO₄ precipitation, gene guntechniques, electroporation, liposomes, lipofection, and the like. Anyof these methods are widely available to one skilled in the art andwould be suitable for use in the present invention. Other suitablemethods are available to one skilled in the art, and it is to beunderstood that the present invention can be accomplished using any ofthe available methods of transfection. Lipofection can be accomplishedby encapsulating an isolated DNA molecule within a liposomal particleand contacting the liposomal particle with the cell membrane of thetarget cell. Liposomes are self-assembling, colloidal particles in whicha lipid bilayer, composed of amphiphilic molecules such as phosphatidylserine or phosphatidyl choline, encapsulates a portion of thesurrounding media such that the lipid bilayer surrounds a hydrophilicinterior. Unilammellar or multilammellar liposomes can be constructedsuch that the interior contains a desired chemical, drug, or, as in theinstant invention, an isolated DNA molecule.

Binding Agents and Modulators

According to another aspect, the present invention further providesbinding agents and modulators, such as antibodies and antigen-bindingfragments thereof, soluble receptors, dominant negative polypeptides,interfering RNAs, etc., that exhibit binding specificity for a GlyRSpolynucleotide (including splice variant species) or polypeptidedisclosed herein, or to a portion, variant or derivative thereof, andmethods of using same. Preferably, such binding agents are effective formodulating one or more of the non-canonical activities mediated by aGlyRS polynucleotide or polypeptide of the invention, and therebyprovide a desired cellular and/or therapeutic effect.

In certain embodiments, for example, the binding agent is one that bindsto a GlyRS polynucleotide or polypeptide of the invention and modulates(e.g., inhibits or enhances) its ability to mediate one or morenon-canonical activity of interest. For example, in some embodiments,the binding agent is one that binds to a GlyRS polynucleotide orpolypeptide and modulates its ability to bind to one or more of itscellular binding partners. In other embodiments, the binding agent isone that binds to a GlyRS polynucleotide or polypeptide of the inventionand modulates its expression and/or activity. Accordingly, such bindingagents may be used to treat or prevent diseases, disorders or otherconditions that are mediated by, or associated with, a GlyRSpolynucleotide or polypeptide of the invention by modulating itsactivity.

In certain illustrative embodiments, the binding agent is an antibody orantigen-binding fragment thereof that specifically binds a GlyRSpolypeptide of the invention. An antibody, or antigen-binding fragmentthereof, is said to “specifically bind,” “immunogically bind,” and/or is“immunologically reactive” to a polypeptide of the invention if itreacts at a detectable level (within, for example, an ELISA assay) withthe polypeptide, and does not react detectably with unrelatedpolypeptides under similar conditions.

etc. Immunological binding, as used in this context, generally refers tothe non-covalent interactions of the type which occur between animmunoglobulin molecule and an antigen for which the immunoglobulin isspecific. The strength, or affinity of immunological bindinginteractions can be expressed in terms of the dissociation constant(K_(d)) of the interaction, wherein a smaller K_(d) represents a greateraffinity. Immunological binding properties of selected polypeptides canbe quantified using methods well known in the art. One such methodentails measuring the rates of antigen-binding site/antigen complexformation and dissociation, wherein those rates depend on theconcentrations of the complex partners, the affinity of the interaction,and on geometric parameters that equally influence the rate in bothdirections. Thus, both the “on rate constant” (k_(on)) and the “off rateconstant” (k_(off)) can be determined by calculation of theconcentrations and the actual rates of association and dissociation. Theratio of k_(off)/k_(on) enables cancellation of all parameters notrelated to affinity, and is thus equal to the dissociation constantK_(d). See, generally, Davies et al. (1990) Annual Rev. Biochem.59:439-473.

An “antigen-binding site,” or “binding portion” of an antibody refers tothe part of the immunoglobulin molecule that participates in antigenbinding. The antigen binding site is formed by amino acid residues ofthe N-terminal variable (“V”) regions of the heavy (“H”) and light (“L”)chains. Three highly divergent stretches within the V regions of theheavy and light chains are referred to as “hypervariable regions” whichare interposed between more conserved flanking stretches known as“framework regions,” or “FRs”. Thus the term “FR” refers to amino acidsequences which are naturally found between and adjacent tohypervariable regions in immunoglobulins. In an antibody molecule, thethree hypervariable regions of a light chain and the three hypervariableregions of a heavy chain are disposed relative to each other in threedimensional space to form an antigen-binding surface. Theantigen-binding surface is complementary to the three-dimensionalsurface of a bound antigen, and the three hypervariable regions of eachof the heavy and light chains are referred to as“complementarity-determining regions,” or “CDRs.”

A binding agent may be, for example, a ribosome, with or without apeptide component, an RNA molecule or a polypeptide. In a preferredembodiment, a binding agent is an antibody or an antigen-bindingfragment thereof. Antibodies may be prepared by any of a variety oftechniques known to those of ordinary skill in the art. See, e.g.,Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring HarborLaboratory, 1988. In general, antibodies can be produced by cell culturetechniques, including the generation of monoclonal antibodies asdescribed herein, or via transfection of antibody genes into suitablebacterial or mammalian cell hosts, in order to allow for the productionof recombinant antibodies. In one technique, an immunogen comprising thepolypeptide is initially injected into any of a wide variety of mammals(e.g., mice, rats, rabbits, sheep or goats). In this step, thepolypeptides of this invention may serve as the immunogen withoutmodification. Alternatively, particularly for relatively shortpolypeptides, a superior immune response may be elicited if thepolypeptide is joined to a carrier protein, such as bovine serum albuminor keyhole limpet hemocyanin. The immunogen is injected into the animalhost, preferably according to a predetermined schedule incorporating oneor more booster immunizations, and the animals are bled periodically.Polyclonal antibodies specific for the polypeptide may then be purifiedfrom such antisera by, for example, affinity chromatography using thepolypeptide coupled to a suitable solid support.

Monoclonal antibodies specific for an polypeptide of interest may beprepared, for example, using the technique of Kohler and Milstein, Eur.J. Immunol. 6:511-519, 1976, and improvements thereto. Briefly, thesemethods involve the preparation of immortal cell lines capable ofproducing antibodies having the desired specificity (i.e., reactivitywith the polypeptide of interest). Such cell lines may be produced, forexample, from spleen cells obtained from an animal immunized asdescribed above. The spleen cells are then immortalized by, for example,fusion with a myeloma cell fusion partner, preferably one that issyngeneic with the immunized animal. A variety of fusion techniques maybe employed. For example, the spleen cells and myeloma cells may becombined with a nonionic detergent for a few minutes and then plated atlow density on a selective medium that supports the growth of hybridcells, but not myeloma cells. A preferred selection technique uses HAT(hypoxanthine, aminopterin, thymidine) selection. After a sufficienttime, usually about 1 to 2 weeks, colonies of hybrids are observed.Single colonies are selected and their culture supernatants tested forbinding activity against the polypeptide. Hybridomas having highreactivity and specificity are preferred.

Monoclonal antibodies may be isolated from the supernatants of growinghybridoma colonies. In addition, various techniques may be employed toenhance the yield, such as injection of the hybridoma cell line into theperitoneal cavity of a suitable vertebrate host, such as a mouse.Monoclonal antibodies may then be harvested from the ascites fluid orthe blood. Contaminants may be removed from the antibodies byconventional techniques, such as chromatography, gel filtration,precipitation, and extraction. The polypeptides of this invention may beused in the purification process in, for example, an affinitychromatography step.

A number of therapeutically useful molecules are known in the art whichcomprise antigen-binding sites that are capable of exhibitingimmunological binding properties of an antibody molecule. Theproteolytic enzyme papain preferentially cleaves IgG molecules to yieldseveral fragments, two of which (the “F(ab)” fragments) each comprise acovalent heterodimer that includes an intact antigen-binding site. Theenzyme pepsin is able to cleave IgG molecules to provide severalfragments, including the “F(ab′)₂” fragment which comprises bothantigen-binding sites. An “Fv” fragment can be produced by preferentialproteolytic cleavage of an IgM, and on rare occasions IgG or IgAimmunoglobulin molecule. Fv fragments are, however, more commonlyderived using recombinant techniques known in the art. The Fv fragmentincludes a non-covalent V_(H)::V_(L) heterodimer including anantigen-binding site which retains much of the antigen recognition andbinding capabilities of the native antibody molecule. Inbar et al.(1972) Proc. Nat. Acad. Sci. USA 69:2659-2662; Hochman et al. (1976)Biochem 15:2706-2710; and Ehrlich et al. (1980) Biochem 19:4091-4096.

A single chain Fv (“sFv”) polypeptide is a covalently linkedV_(H)::V_(L) heterodimer which is expressed from a gene fusion includingV_(H)- and V_(L)-encoding genes linked by a peptide-encoding linker.Huston et al. (1988) Proc. Nat. Acad. Sci. USA 85(16):5879-5883. Anumber of methods have been described to discern chemical structures forconverting the naturally aggregated—but chemically separated-light andheavy polypeptide chains from an antibody V region into an sFv moleculewhich will fold into a three dimensional structure substantially similarto the structure of an antigen-binding site. See, e.g., U.S. Pat. Nos.5,091,513 and 5,132,405, to Huston et al.; and U.S. Pat. No. 4,946,778,to Ladner et al.

Each of the above-described molecules includes a heavy chain and a lightchain CDR set, respectively interposed between a heavy chain and a lightchain FR set which provide support to the CDRS and define the spatialrelationship of the CDRs relative to each other. As used herein, theterm “CDR set” refers to the three hypervariable regions of a heavy orlight chain V region. Proceeding from the N-terminus of a heavy or lightchain, these regions are denoted as “CDR1,” “CDR2,” and “CDR3”respectively. An antigen-binding site, therefore, includes six CDRs,comprising the CDR set from each of a heavy and a light chain V region.A polypeptide comprising a single CDR, (e.g., a CDR1, CDR2 or CDR3) isreferred to herein as a “molecular recognition unit.” Crystallographicanalysis of a number of antigen-antibody complexes has demonstrated thatthe amino acid residues of CDRs form extensive contact with boundantigen, wherein the most extensive antigen contact is with the heavychain CDR3. Thus, the molecular recognition units are primarilyresponsible for the specificity of an antigen-binding site.

As used herein, the term “FR set” refers to the four flanking amino acidsequences which frame the CDRs of a CDR set of a heavy or light chain Vregion. Some FR residues may contact bound antigen; however, FRs areprimarily responsible for folding the V region into the antigen-bindingsite, particularly the FR residues directly adjacent to the CDRS. WithinFRs, certain amino residues and certain structural features are veryhighly conserved. In this regard, all V region sequences contain aninternal disulfide loop of around 90 amino acid residues. When the Vregions fold into a binding-site, the CDRs are displayed as projectingloop motifs which form an antigen-binding surface. It is generallyrecognized that there are conserved structural regions of FRs whichinfluence the folded shape of the CDR loops into certain “canonical”structures—regardless of the precise CDR amino acid sequence. Further,certain FR residues are known to participate in non-covalent interdomaincontacts which stabilize the interaction of the antibody heavy and lightchains.

A number of “humanized” antibody molecules comprising an antigen-bindingsite derived from a non-human immunoglobulin have been described,including chimeric antibodies having rodent V regions and theirassociated CDRs fused to human constant domains (Winter et al. (1991)Nature 349:293-299; Lobuglio et al. (1989) Proc. Nat. Acad. Sci. USA86:4220-4224; Shaw et al. (1987) J Immunol. 138:4534-4538; and Brown etal. (1987) Cancer Res. 47:3577-3583), rodent CDRs grafted into a humansupporting FR prior to fusion with an appropriate human antibodyconstant domain (Riechmann et al. (1988) Nature 332:323-327; Verhoeyenet al. (1988) Science 239:1534-1536; and Jones et al. (1986) Nature321:522-525), and rodent CDRs supported by recombinantly veneered rodentFRs (European Patent Publication No. 519,596, published Dec. 23, 1992).These “humanized” molecules are designed to minimize unwantedimmunological response toward rodent antibody molecules which limits theduration and effectiveness of therapeutic applications of those moietiesin human recipients.

As used herein, the terms “veneered FRs” and “recombinantly veneeredFRs” refer to the selective replacement of FR residues from, e.g., arodent heavy or light chain V region, with human FR residues in order toprovide a xenogeneic molecule comprising an antigen-binding site whichretains substantially all of the native FR polypeptide foldingstructure. Veneering techniques are based on the understanding that theligand binding characteristics of an antigen-binding site are determinedprimarily by the structure and relative disposition of the heavy andlight chain CDR sets within the antigen-binding surface. Davies et al.(1990) Ann. Rev. Biochem. 59:439-473. Thus, antigen binding specificitycan be preserved in a humanized antibody only wherein the CDRstructures, their interaction with each other, and their interactionwith the rest of the V region domains are carefully maintained. By usingveneering techniques, exterior (e.g., solvent-accessible) FR residueswhich are readily encountered by the immune system are selectivelyreplaced with human residues to provide a hybrid molecule that compriseseither a weakly immunogenic, or substantially non-immunogenic veneeredsurface.

In another embodiment of the invention, monoclonal antibodies of thepresent invention may be coupled to one or more agents of interest. Forexample, a therapeutic agent may be coupled (e.g., covalently bonded) toa suitable monoclonal antibody either directly or indirectly (e.g., viaa linker group). A direct reaction between an agent and an antibody ispossible when each possesses a substituent capable of reacting with theother. For example, a nucleophilic group, such as an amino or sulfhydrylgroup, on one may be capable of reacting with a carbonyl-containinggroup, such as an anhydride or an acid halide, or with an alkyl groupcontaining a good leaving group (e.g., a halide) on the other.

Alternatively, it may be desirable to couple a therapeutic agent and anantibody via a linker group. A linker group can function as a spacer todistance an antibody from an agent in order to avoid interference withbinding capabilities. A linker group can also serve to increase thechemical reactivity of a substituent on an agent or an antibody, andthus increase the coupling efficiency. An increase in chemicalreactivity may also facilitate the use of agents, or functional groupson agents, which otherwise would not be possible.

It will be evident to those skilled in the art that a variety ofbifunctional or polyfunctional reagents, both homo- andhetero-functional (such as those described in the catalog of the PierceChemical Co., Rockford, Ill.), may be employed as the linker group.Coupling may be effected, for example, through amino groups, carboxylgroups, sulfhydryl groups or oxidized carbohydrate residues. There arenumerous references describing such methodology, e.g., U.S. Pat. No.4,671,958, to Rodwell et al.

Where a therapeutic agent is more potent when free from the antibodyportion of the immunoconjugates of the present invention, it may bedesirable to use a linker group which is cleavable during or uponinternalization into a cell. A number of different cleavable linkergroups have been described. The mechanisms for the intracellular releaseof an agent from these linker groups include cleavage by reduction of adisulfide bond (e.g., U.S. Pat. No. 4,489,710, to Spitler), byirradiation of a photolabile bond (e.g., U.S. Pat. No. 4,625,014, toSenter et al.), by hydrolysis of derivatized amino acid side chains(e.g., U.S. Pat. No. 4,638,045, to Kohn et al.), by serumcomplement-mediated hydrolysis (e.g., U.S. Pat. No. 4,671,958, toRodwell et al.), and acid-catalyzed hydrolysis (e.g., U.S. Pat. No.4,569,789, to Blattler et al.).

It may be desirable to couple more than one agent to an antibody. In oneembodiment, multiple molecules of an agent are coupled to one antibodymolecule. In another embodiment, more than one type of agent may becoupled to one antibody. Regardless of the particular embodiment,immunoconjugates with more than one agent may be prepared in a varietyof ways. For example, more than one agent may be coupled directly to anantibody molecule, or linkers that provide multiple sites for attachmentcan be used.

In other aspects of the invention, modulators/binding agents accordingto the present invention can comprise one or more interfering RNA (RNAi)sequences specific for a GlyRS polynucleotide. RNA interference methodsusing interfering RNAi molecules may be used to disrupt the expressionof a desired gene or polynucleotide of interest, such as a GlyRS gene orsplice variant in order to achieve a desired cellular and/or therapeuticeffect.

In particular embodiments, the interfering RNA is a small interferingRNA (siRNA). SiRNAs are RNA duplexes typically 19-30 nucleotides longthat can associate with a cytoplasmic multi-protein complex known asRNAi-induced silencing complex (RISC). RISC loaded with siRNA mediatesthe degradation of homologous mRNA transcripts. Therefore, siRNA can bedesigned to knock down protein expression with high specificity. Whilethe first described RNAi molecules were RNA:RNA hybrids comprising bothan RNA sense and an RNA antisense strand, it has now been demonstratedthat DNA sense:RNA antisense hybrids, RNA sense:DNA antisense hybrids,and DNA:DNA hybrids are capable of mediating RNAi (Lamberton, J. S. andChristian, A. T., (2003) Molecular Biotechnology 24:111-119). Thus, theinvention includes the use of RNAi molecules comprising any of thesedifferent types of double-stranded molecules. In addition, it isunderstood that RNAi molecules may be used and introduced to cells in avariety of forms. Accordingly, as used herein, RNAi moleculesencompasses any and all molecules capable of inducing an RNAi responsein cells, including, but not limited to, double-stranded polynucleotidescomprising two separate strands, i.e. a sense strand and an antisensestrand, e.g., small interfering RNA (siRNA); polynucleotides comprisinga hairpin loop of complementary sequences, which forms a double-strandedregion, e.g., small hairpin RNA (shRNA) molecules, and expressionvectors that express one or more polynucleotides capable of forming adouble-stranded polynucleotide alone or in combination with anotherpolynucleotide.

RNAi molecules targeting specific GlyRS polynucleotides can be readilyprepared according to procedures known in the art. Structuralcharacteristics of effective siRNA molecules have been identified.Elshabir, S. M. et al. (2001) Nature 411:494-498 and Elshabir, S. M. etal. (2001), EMBO 20:6877-6888. Accordingly, one of skill in the artwould understand that a wide variety of different siRNA molecules may beused to target a specific gene or transcript. In certain embodiments,siRNA molecules according to the invention are typically double-strandedand 16-30 or 18-25 nucleotides in length, including each integer inbetween. In one embodiment, a siRNA is about 21 nucleotides in length.In certain embodiments, siRNAs have 0-7 nucleotide 3′ overhangs or 0-4nucleotide 5′ overhangs. In one embodiment, a siRNA molecule has a twonucleotide 3′ overhang. In one embodiment, a siRNA is 21 nucleotides inlength with two nucleotide 3′ overhangs (i.e. they contain a 19nucleotide complementary region between the sense and antisensestrands). In certain embodiments, the overhangs are UU or dTdT 3′overhangs.

In one embodiment, siRNA target sites are selected by scanning thetarget mRNA transcript sequence for the occurrence of AA dinucleotidesequences. Each AA dinucleotide sequence in combination with the 3′adjacent approximately 19 nucleotides are potential siRNA target sites.In one embodiment, siRNA target sites are preferentially not locatedwithin the 5′ and 3′ untranslated regions (UTRs) or regions near thestart codon (within approximately 75 bases), since proteins that bindregulatory regions may interfere with the binding of the siRNPendonuclease complex (Elshabir, S. et al. Nature 411:494-498 (2001);Elshabir, S. et al. EMBO J. 20:6877-6888 (2001)). In addition, potentialtarget sites may be compared to an appropriate genome database, such asBLASTN 2.0.5, available on the NCBI server at www.ncbi.nlm, andpotential target sequences with significant homology to other codingsequences eliminated.

In particular embodiments, the interfering RNA is a short hairpin RNA.ShRNAs contain a stem loop structure. In certain embodiments, they maycontain variable stem lengths, typically from 19 to 29 nucleotides inlength, or any number in between. In certain embodiments, hairpinscontain 19 to 21 nucleotide stems, while in other embodiments, hairpinscontain 27 to 29 nucleotide stems. In certain embodiments, loop size isbetween 4 to 23 nucleotides in length, although the loop size may belarger than 23 nucleotides without significantly affecting silencingactivity. ShRNA molecules may contain mismatches, for example G-Umismatches between the two strands of the shRNA stem without decreasingpotency. In fact, in certain embodiments, shRNAs are designed to includeone or several G-U pairings in the hairpin stem to stabilize hairpinsduring propagation in bacteria, for example. However, complementaritybetween the portion of the stem that binds to the target mRNA (antisensestrand) and the mRNA is typically required, and even a single base pairmismatch is this region may abolish silencing. 5′ and 3′ overhangs arenot required, although they may be present.

In certain aspects, an interfering RNA or siRNA comprises one or moremodifications, such as a modified nucleoside or a modified phosphatelinkage. In one embodiment, a siRNA comprises at least one modifiednucleotide in the double-stranded region. In some embodiments, themodified siRNA contains at least one 2′OMe purine or pyrimidinenucleotide such as a 2′OMe-guanosine, 2′OMe-uridine, 2′OMe-adenosine,and/or 2′OMe-cytosine nucleotide. Examples of modified nucleotidessuitable for use in the present invention include, but are not limitedto, ribonucleotides having a 2′-O-methyl (2′OMe), 2′-deoxy-2′-fluoro(2′F), 2′-deoxy, 5-C-methyl, 2′-O-(2-methoxyethyl) (MOE), 4′-thio,2′-amino, or 2′-C-allyl group.

Non-limiting examples of phosphate backbone modifications (i.e.,resulting in modified internucleotide linkages) that may be present ininterfering RNA of the present invention include phosphorothioate,phosphorodithioate, methylphosphonate, phosphotriester, morpholino,amidate, carbamate, carboxymethyl, acetamidate, polyamide, sulfonate,sulfonamide, sulfamate, formacetal, thioformacetal, and alkylsilylsubstitutions (see, e.g., Hunziker et al., Nucleic Acid Analogues:Synthesis and Properties, in Modern Synthetic Methods, VCH, 331-417(1995); Mesmaeker et al., Novel Backbone Replacements forOligonucleotides, in Carbohydrate Modifications in Antisense Research,ACS, 24-39 (1994)). Such chemical modifications can occur at the 5′-endand/or 3′-end of the sense strand, antisense strand, or both strands ofthe siRNA.

In particular embodiments, the interfering RNA targets a particularGlyRS mRNA expressed in a cell. Accordingly, the interfering RNA causesa reduction in expression of the targeted gene in the cell contactedwith the interfering RNA. In particular embodiments, cells contactedwith the interfering RNA under conditions and for a time sufficient forRNA interference to occur express less than 90%, less than 80%, lessthan 70%, less than 60%, less than 50%, less than 40%, less than 30%,less than 20%, or less than 10% the amount of the targeted gene asexpressed by the same cell type not contacted with the interfering RNA.Expression may be measured as either protein expression or mRNAexpression, or as microRNA expression. Levels of the protein expressedby the target gene may be readily determined using routine procedures,e.g., such as Western blotting or FACS. Levels of RNA expressed by atargeted gene may be readily determined using routine procedures such asRT-PCR.

An interfering RNA used in the present invention comprises a regioncorresponding to or complementary to a region of a target GlyRS gene. Inpreferred embodiments, this complementary region is completelycomplementary, while in other embodiments, it may comprise one or moremismatches. In certain embodiments, the complementary region is between19 and 25 bases in length or between 19 and 21 bases in length.

Also included in modulators/binding agents of the invention are, forexample, dominant negative forms of a GlyRS polypeptide, such as amutant and/or truncated GlyRS polypeptide that can bind a GlyRSpolypeptide of the invention and interfere with or antagonize one ormore of its non-canonical activities.

Formulation and Administration

The compositions of the invention (e.g., polypeptides, polynucleotides,antibodies, etc.) are generally formulated inpharmaceutically-acceptable or physiologically-acceptable solutions foradministration to a cell, tissue or animal, either alone, or incombination with one or more other modalities of therapy. It will alsobe understood that, if desired, the compositions of the invention may beadministered in combination with other agents as well, such as, e.g.,other proteins or polypeptides or various pharmaceutically-activeagents. There is virtually no limit to other components that may also beincluded in the compositions, provided that the additional agents do notadversely affect properties of a GlyRS polypeptide of the invention.

In the pharmaceutical compositions of the invention, formulation ofpharmaceutically-acceptable excipients and carrier solutions iswell-known to those of skill in the art, as is the development ofsuitable dosing and treatment regimens for using the particularcompositions described herein in a variety of treatment regimens,including e.g., oral, parenteral, intravenous, intranasal, intracranialand intramuscular administration and formulation.

In certain applications, the pharmaceutical compositions disclosedherein may be delivered via oral administration to a subject. As such,these compositions may be formulated with an inert diluent or with anassimilable edible carrier, or they may be enclosed in hard- orsoft-shell gelatin capsule, or they may be compressed into tablets, orthey may be incorporated directly with the food of the diet.

In certain circumstances it will be desirable to deliver thepharmaceutical compositions disclosed herein parenterally,intravenously, intramuscularly, or even intraperitoneally as described,for example, in U.S. Pat. Nos. 5,543,158; 5,641,515 and 5,399,363 (eachspecifically incorporated herein by reference in its entirety).Solutions of the active compounds as free base or pharmacologicallyacceptable salts may be prepared in water suitably mixed with asurfactant, such as hydroxypropylcellulose. Dispersions may also beprepared in glycerol, liquid polyethylene glycols, and mixtures thereofand in oils. Under ordinary conditions of storage and use, thesepreparations contain a preservative to prevent the growth ofmicroorganisms.

The pharmaceutical forms suitable for injectable use include sterileaqueous solutions or dispersions and sterile powders for theextemporaneous preparation of sterile injectable solutions ordispersions (U.S. Pat. No. 5,466,468, specifically incorporated hereinby reference in its entirety). In all cases the form should be sterileand should be fluid to the extent that easy syringability exists. Itshould be stable under the conditions of manufacture and storage andshould be preserved against the contaminating action of microorganisms,such as bacteria and fungi. The carrier can be a solvent or dispersionmedium containing, for example, water, ethanol, polyol (e.g., glycerol,propylene glycol, and liquid polyethylene glycol, and the like),suitable mixtures thereof, and/or vegetable oils. Proper fluidity may bemaintained, for example, by the use of a coating, such as lecithin, bythe maintenance of the required particle size in the case of dispersionand by the use of surfactants. The prevention of the action ofmicroorganisms can be facilitated by various antibacterial andantifungal agents, for example, parabens, chlorobutanol, phenol, sorbicacid, thimerosal, and the like. In many cases, it will be preferable toinclude isotonic agents, for example, sugars or sodium chloride.Prolonged absorption of the injectable compositions can be brought aboutby the use in the compositions of agents delaying absorption, forexample, aluminum monostearate and gelatin.

For parenteral administration in an aqueous solution, for example, thesolution should be suitably buffered if necessary and the liquid diluentfirst rendered isotonic with sufficient saline or glucose. Theseparticular aqueous solutions are especially suitable for intravenous,intramuscular, subcutaneous and intraperitoneal administration. In thisconnection, a sterile aqueous medium that can be employed will be knownto those of skill in the art in light of the present disclosure. Forexample, one dosage may be dissolved in 1 ml of isotonic NaCl solutionand either added to 1000 ml of hypodermoclysis fluid or injected at theproposed site of infusion (see, e.g., Remington's PharmaceuticalSciences, 15th Edition, pp. 1035-1038 and 1570-1580). Some variation indosage will necessarily occur depending on the condition of the subjectbeing treated. The person responsible for administration will, in anyevent, determine the appropriate dose for the individual subject.Moreover, for human administration, preparations should meet sterility,pyrogenicity, and the general safety and purity standards as required byFDA Office of Biologics standards.

Sterile injectable solutions can be prepared by incorporating the activecompounds in the required amount in the appropriate solvent with thevarious other ingredients enumerated above, as required, followed byfiltered sterilization. Generally, dispersions are prepared byincorporating the various sterilized active ingredients into a sterilevehicle which contains the basic dispersion medium and the requiredother ingredients from those enumerated above. In the case of sterilepowders for the preparation of sterile injectable solutions, thepreferred methods of preparation are vacuum-drying and freeze-dryingtechniques which yield a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

The compositions disclosed herein may be formulated in a neutral or saltform. Pharmaceutically-acceptable salts, include the acid addition salts(formed with the free amino groups of the protein) and which are formedwith inorganic acids such as, for example, hydrochloric or phosphoricacids, or such organic acids as acetic, oxalic, tartaric, mandelic, andthe like. Salts formed with the free carboxyl groups can also be derivedfrom inorganic bases such as, for example, sodium, potassium, ammonium,calcium, or ferric hydroxides, and such organic bases as isopropylamine,trimethylamine, histidine, procaine and the like. Upon formulation,solutions will be administered in a manner compatible with the dosageformulation and in such amount as is therapeutically effective. Theformulations are easily administered in a variety of dosage forms suchas injectable solutions, drug-release capsules, and the like.

As used herein, “carrier” includes any and all solvents, dispersionmedia, vehicles, coatings, diluents, antibacterial and antifungalagents, isotonic and absorption delaying agents, buffers, carriersolutions, suspensions, colloids, and the like. The use of such mediaand agents for pharmaceutically active substances is well known in theart. Except insofar as any conventional media or agent is incompatiblewith the active ingredient, its use in the therapeutic compositions iscontemplated. Supplementary active ingredients can also be incorporatedinto the compositions.

The phrase “pharmaceutically-acceptable” refers to molecular entitiesand compositions that do not produce an allergic or similar untowardreaction when administered to a human. The preparation of an aqueouscomposition that contains a protein as an active ingredient is wellunderstood in the art. Typically, such compositions are prepared asinjectables, either as liquid solutions or suspensions; solid formssuitable for solution in, or suspension in, liquid prior to injectioncan also be prepared. The preparation can also be emulsified.

In certain embodiments, the pharmaceutical compositions may be deliveredby intranasal sprays, inhalation, and/or other aerosol deliveryvehicles. Methods for delivering genes, polynucleotides, and peptidecompositions directly to the lungs via nasal aerosol sprays has beendescribed e.g., in U.S. Pat. Nos. 5,756,353 and 5,804,212 (eachspecifically incorporated herein by reference in its entirety).Likewise, the delivery of drugs using intranasal microparticle resins(Takenaga et al., 1998) and lysophosphatidyl-glycerol compounds (U.S.Pat. No. 5,725,871, specifically incorporated herein by reference in itsentirety) are also well-known in the pharmaceutical arts. Likewise,transmucosal drug delivery in the form of a polytetrafluoroetheylenesupport matrix is described in U.S. Pat. No. 5,780,045 (specificallyincorporated herein by reference in its entirety).

In certain embodiments, the delivery may occur by use of liposomes,nanocapsules, microparticles, microspheres, lipid particles, vesicles,and the like, for the introduction of the compositions of the presentinvention into suitable host cells. In particular, the compositions ofthe present invention may be formulated for delivery either encapsulatedin a lipid particle, a liposome, a vesicle, a nanosphere, a nanoparticleor the like. The formulation and use of such delivery vehicles can becarried out using known and conventional techniques.

Kits Comprising Compositions of the Invention

The invention, in other aspects, provides kits comprising one or morecontainers filled with one or more of the polypeptides, polynucleotides,antibodies, multiunit complexes, compositions thereof, etc., of theinvention, as described herein. The kits can include writteninstructions on how to use such compositions (e.g., to modulate cellularsignaling, angiogenesis, cancer, inflammatory conditions, etc.).

The kits herein may also include a one or more additional therapeuticagents or other components suitable or desired for the indication beingtreated. An additional therapeutic agent may be contained in a secondcontainer, if desired. Examples of additional therapeutic agentsinclude, but are not limited to antineoplastic agents, anti-inflammatoryagents, antibacterial agents, antiviral agents, angiogenic agents, etc.

The kits herein can also include one or more syringes or othercomponents necessary or desired to facilitate an intended mode ofdelivery (e.g., stents, implantable depots, etc.).

Methods of Use

In another aspect, the present invention relates to methods of using thecompositions of the present invention (e.g., polynucleotides,polypeptides, etc.), or binding agents or other modulators of suchcompositions (e.g., antibodies, interfering RNAs, antisense RNAs,dominant negative polypeptides, small molecule modulators, etc.) fortreating a cell, tissue or subject in order to achieve a desiredcellular and/or therapeutic effect. The cells or tissues that may bemodulated by the present invention are preferably mammalian cells ortissues, or more preferably human cells or tissues. Such cells ortissues can be of a healthy state or of a diseased state.

In certain embodiments, for example, methods are provided for modulatingtherapeutically relevant cellular activities by contacting a cell with aGlyRS composition as described herein. Such cellular activities caninclude, but not limited to, cellular metabolism, cell differentiation,cell proliferation, cell death, cell mobilization, cell migration, cellsignaling, modulation of cytokine production and/or secretion, genetranscription, mRNA translation, cell impedence, and the like. In morespecific embodiments, cellular activities to be modulated according tothe present invention include, for example, Akt-mediated cell signaling,Erk1/2-mediated cell signaling, GPCR-mediated cell signaling,endothelial cell tube formation, and cell binding. In other specificembodiments, cellular activities include, for example, modulation ofCD71 and/or CD80. In yet other specific embodiments, cellular activitiesinclude, for example, modulation of cytokine production and/or release,wherein the cytokine is selected from the group consisting of TNF-α,IL1-β, IL-6, IL-8, IL-10, IL-12p40, MIP1-α, MIP-1β, GRO-α, MCP-1 andIL-1ra. In yet other specific embodiments, cellular activities include,for example, metabolic regulation through modulation of cellularglucose, glucagon, glycerol and/or free fatty acid. In yet otherspecific embodiments, cellular activities include, for example,modulation of neurogenesis or neuroprotection. Accordingly, the GlyRScompositions may be employed in treating essentially any cell or tissueor subject that would benefit from modulation of one or more suchactivities.

The GlyRS compositions may also be used in any of a number oftherapeutic contexts including, for example, those relating to thetreatment or prevention of neoplastic diseases, immune system diseases(e.g., autoimmune diseases and inflammation), infectious diseases,metabolic diseases, neuronal/neurological diseases,muscular/cardiovascular diseases, diseases associated with aberranthematopoiesis, diseases associated with aberrant angiogenesis, diseasesassociated with aberrant cell survival, and others.

For example, in certain illustrative embodiments, the GlyRS compositionsof the invention may be used to modulate angiogenesis, e.g., viamodulation of endothelial cell proliferation and/or signaling.Endothelial cell proliferation and/or signaling may be monitored usingan appropriate cell line (e.g., human microvascular endothelial lungcells (HMVEC-L) and human umbilical vein endothelial cells (HUVEC)), andusing an appropriate assay (e.g., endothelial cell migration assays,endothelial cell proliferation assays, tube-forming assays, matrigelplug assays, etc.), many of which are known and available in the art.

Therefore, in related embodiments, the compositions of the invention maybe employed in the treatment of essentially any cell or tissue orsubject that would benefit from modulation of angiogenesis. For example,in some embodiments, a cell or tissue or subject experiencing orsusceptible to angiogenesis (e.g., an angiogenic condition) may becontacted with a suitable composition of the invention to inhibit anangiogenic condition. In other embodiments, a cell or tissueexperiencing or susceptible to insufficient angiogenesis (e.g., anangiostatic condition) may be contacted with an appropriate compositionof the invention in order to interfere with angiostatic activity and/orpromote angiogenesis.

Illustrative examples of angiogenic conditions include, but are notlimited to, age-related macular degeneration (AMD), cancer (both solidand hematologic), developmental abnormalities (organogenesis), diabeticblindness, endometriosis, ocular neovascularization, psoriasis,rheumatoid arthritis (RA), and skin discolorations (e.g., hemangioma,nevus flammeus or nevus simplex). Examples of anti-angiogenic conditionsinclude, but are not limited to, cardiovascular disease, restenosis,tissue damage after reperfusion of ischemic tissue or cardiac failure,chronic inflammation and wound healing.

The compositions of the invention may also be useful as immunomodulatorsfor treating anti- or pro-inflammatory indications by modulating thecells that mediate, either directly or indirectly, autoimmune and/orinflammatory diseases, conditions and disorders. The utility of thecompositions of the invention as immunomodulators can be monitored usingany of a number of known and available techniques in the art including,for example, migration assays (e.g., using leukocytes or lymphocytes) orcell viability assays (e.g., using B-cells, T-cells, monocytes or NKcells).

Illustrative immune system diseases, disorders or conditions that may betreated according to the present invention include, but are not limitedto, primary immuodeficiencies, immune-mediated thrombocytopenia,Kawasaki syndrome, bone marrow transplant (for example, recent bonemarrow transplant in adults or children), chronic B cell lymphocyticleukemia, HIV infection (for example, adult or pediatric HIV infection),chronic inflammatory demyelinating polyneuropathy, post-transfusionpurpura, and the like.

Additionally, further diseases, disorders and conditions includeGuillain-Barre syndrome, anemia (for example, anemia associated withparvovirus B19, patients with stable multiple myeloma who are at highrisk for infection (for example, recurrent infection), autoimmunehemolytic anemia (for example, warm-type autoimmune hemolytic anemia),thrombocytopenia (for example, neonatal thrombocytopenia), andimmune-mediated neutropenia, transplantation (for example,cytomegalovirus (CMV)-negative recipients of CMV-positive organs),hypogammaglobulinemia (for example, hypogammaglobulinemic neonates withrisk factor for infection or morbidity), epilepsy (for example,intractable epilepsy), systemic vasculitic syndromes, myasthenia gravis(for example, decompensation in myasthenia gravis), dermatomyositis, andpolymyositis.

Further autoimmune diseases, disorders and conditions include, but arenot limited to, autoimmune hemolytic anemia, autoimmune neonatalthrombocytopenia, idiopathic thrombocytopenia purpura,autoimmunocytopenia, hemolytic anemia, antiphospholipid syndrome,dermatitis, allergic encephalomyelitis, myocarditis, relapsingpolychondritis, rheumatic heart disease, glomerulonephritis (forexample, IgA nephropathy), multiple sclerosis, neuritis, uveitisophthalmia, polyendocrinopathies, purpura (for example,Henloch-Scoenlein purpura), Reiter's disease, stiff-man syndrome,autoimmune pulmonary inflammation, Guillain-Barre Syndrome, insulindependent diabetes mellitis, and autoimmune inflammatory eye disease.

Additional autoimmune diseases, disorders or conditions include, but arenot limited to, autoimmune thyroiditis; hypothyroidism, includingHashimoto's thyroiditis and thyroiditis characterized, for example, bycell-mediated and humoral thyroid cytotoxicity; SLE (which is oftencharacterized, for example, by circulating and locally generated immunecomplexes); Goodpasture's syndrome (which is often characterized, forexample, by anti-basement membrane antibodies); pemphigus (which isoften characterized, for example, by epidermal acantholytic antibodies);receptor autoimmunities such as, for example, Graves' disease (which isoften characterized, for example, by antibodies to a thyroid stimulatinghormone receptor) myasthenia gravis, (which is often characterized, forexample, by acetylcholine receptor antibodies); insulin resistance(which is often characterized, for example, by insulin receptorantibodies); autoimmune hemolytic anemia (which is often characterized,for example, by phagocytosis of antibody-sensitized red blood cells);and autoimmune thrombocytopenic purpura (which is often characterized,for example, by phagocytosis of antibody-sensitized platelets).

Further autoimmune diseases, disorders or conditions include, but arenot limited to, rheumatoid arthritis (which is often characterized, forexample, by immune complexes in joints); scleroderma with anti-collagenantibodies (which is often characterized, for example, by nucleolar andother nuclear antibodies); mixed connective tissue disease, (which isoften characterized, for example, by antibodies to extractable nuclearantigens, for example, ribonucleoprotein); polymyositis/dermatomyositis(which is often characterized, for example, by nonhistone anti-nuclearantibodies); pernicious anemia (which is often characterized, forexample, by antiparietal cell, antimicrosome, and anti-intrinsic factorantibodies); idiopathic Addison's disease (which is often characterized,for example, by humoral and cell-mediated adrenal cytotoxicity);infertility (which is often characterized, for example, byantispennatozoal antibodies); glomerulonephritis (which is oftencharacterized, for example, by glomerular basement membrane antibodiesor immune complexes); primary glomerulonephritis, IgA nephropathy;bullous pemphigoid (which is often characterized, for example, by IgGand complement in the basement membrane); Sjogren's syndrome (which isoften characterized, for example, by multiple tissue antibodies and/orthe specific nonhistone antinuclear antibody (SS-B)); diabetes mellitus(which is often characterized, for example, by cell-mediated and humoralislet cell antibodies); and adrenergic drug resistance, includingadrenergic drug resistance with asthma or cystic fibrosis (which isoften characterized, for example, by beta-adrenergic receptorantibodies).

Still further autoimmune diseases, disorders or conditions include, butare not limited to chronic active hepatitis (which is oftencharacterized, for example by smooth muscle antibodies); primary biliarycirrhosis (which is often characterized, for example, byanti-mitchondrial antibodies); other endocrine gland failure (which ischaracterized, for example, by specific tissue antibodies in somecases); vitiligo (which is often characterized, for example, byanti-melanocyte antibodies); vasculitis (which is often characterized,for example, by immunoglobulin and complement in vessel walls and/or lowserum complement); post-myocardial infarction conditions (which areoften characterized, for example, by anti-myocardial antibodies);cardiotomy syndrome (which is often characterized, for example, byanti-myocardial antibodies); urticaria (which is often characterized,for example, by IgG and IgM antibodies to IgE); atopic dermatitis (whichis often characterized, for example, by IgG and IgM antibodies to IgE);asthma (which is often characterized, for example, by IgG and IgMantibodies to IgE); inflammatory myopathies; and other inflammatory,granulomatous, degenerative, and atrophic disorders.

In other embodiments, the GlyRS compositions of the invention may beused to modulate cellular proliferation and/or survival and,accordingly, for treating or preventing diseases, disorders orconditions characterized by abnormalities in cellular proliferationand/or survival. For example, in certain embodiments, the GlyRScompositions may be used to modulate apoptosis and/or to treat diseasesor conditions associated with abnormal apoptosis. Apoptosis is the termused to describe the cell signaling cascade known as programmed celldeath. Various therapeutic indications exist for molecules that induceapoptosis (e.g. cancer), as well as those that inhibit apoptosis (e.g.stroke, myocardial infarction, sepsis, etc.). Apoptosis can be monitoredby any of a number of available techniques known and available in theart including, for example, assays that measure fragmentation of DNA,alterations in membrane asymmetry, activation of apoptotic caspasesand/or release of cytochrome C and AIF.

Illustrative diseases associated with increased cell survival, or theinhibition of apoptosis include, but are not limited to, cancers (suchas follicular lymphomas, carcinomas, and hormone-dependent tumors,including, but not limited to colon cancer, cardiac tumors, pancreaticcancer, melanoma, retinoblastoma, glioblastoma, lung cancer, intestinalcancer, testicular cancer, stomach cancer, neuroblastoma, myxoma, myoma,lymphoma, endothelioma, osteoblastoma, osteoclastoma, osteosarcoma,chondrosarcoma, adenoma, breast cancer, prostate cancer, Kaposi'ssarcoma and ovarian cancer); autoimmune disorders (such as, multiplesclerosis, Sjogren's syndrome, Graves' disease, Hashimoto's thyroiditis,autoimmune diabetes, biliary cirrhosis, Behcet's disease, Crohn'sdisease, polymyositis, systemic lupus erythematosus and immune-relatedglomerulonephritis, autoimmune gastritis, autoimmune thrombocytopenicpurpura, and rheumatoid arthritis), viral infections (such as herpesviruses, pox viruses and adenoviruses), inflammation, graft vs. hostdisease (acute and/or chronic), acute graft rejection, and chronic graftrejection.

Further illustrative diseases or conditions associated with increasedcell survival include, but are not limited to, progression and/ormetastases of malignancies and related disorders such as leukemia(including acute leukemias (for example, acute lymphocytic leukemia,acute myelocytic leukemia, including myeloblastic, promyelocytic,myelomonocytic, monocytic, and erythroleukemia)) and chronic leukemias(for example, chronic myelocytic (granulocytic) leukemia and chroniclymphocytic leukemia), myelodysplastic syndrome, polycythemia vera,lymphomas (for example, Hodgkin's disease and non-Hodgkin's disease),multiple myeloma, Waldenstrom's macroglobulinemia, heavy chain diseases,and solid tumors including, but not limited to, sarcomas and carcinomassuch as fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma,osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma,lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma,Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma,pancreatic cancer, breast cancer, ovarian cancer, prostate cancer,squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweatgland carcinoma, sebaceous gland carcinoma, papillary carcinoma,papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma,bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile ductcarcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilm's tumor,cervical cancer, testicular tumor, lung carcinoma, small cell lungcarcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma,medulloblastoma, craniopharyngioma, ependymoma, pinealoma,hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma,melanoma, neuroblastoma, and retinoblastoma.

Illustrative diseases associated with increased apoptosis include, butare not limited to, AIDS (such as HIV-induced nephropathy and HIVencephalitis), neurodegenerative disorders (such as Alzheimer's disease,Parkinson's disease, amyotrophic lateral sclerosis, retinitispigmentosa, cerebellar degeneration and brain tumor or prior associateddisease), autoimmune disorders such as multiple sclerosis, Sjogren'ssyndrome, Graves' disease, Hashimoto's thyroiditis, autoimmune diabetes,biliary cirrhosis, Behcet's disease, Crohn's disease, polymyositis,systemic lupus erythematosus, immune-related glomerulonephritis,autoimmune gastritis, thrombocytopenic purpura, rheumatoid arthritis,myelodysplastic syndromes (such as aplastic anemia), graft vs. hostdisease (acute and/or chronic), ischemic injury (such as that caused bymyocardial infarction, stroke and reperfusion injury), liver injury ordisease (for example, hepatitis related liver injury, cirrhosis,ischemia/reperfusion injury, cholestosis (bile duct injury) and livercancer), toxin-induced liver disease (such as that caused by alcohol),septic shock, ulcerative colitis, cachexia, and anorexia.

In still further embodiments, the compositions of the invention may beused in the treatment of neuronal/neurological diseases or disorders,illustrative examples of which include Parkinson's disease, Alzheimer'sdisease, Pick's Disease, Creutzfeldt-Jacob disease, Huntington's chorea,alternating hemiplegia, amyotrophic lateral sclerosis, ataxia, cerebralpalsy, chronic fatigue syndrome, chronic pain syndromes, congenitalneurological anomalies, cranial nerve diseases, delirium, dementia,demyelinating diseases, dysautonomia, epilepsy, headaches, Huntington'sdisease, hydrocephalus, meningitis, movement disorders, muscle diseases,nervous system neoplasms, neurocutaneous syndromes, neurodegenerativediseases, neurotoxicity syndromes, ocular motility disorders, peripheralnervous system disorders, pituitary disorders, porencephaly, Rettsyndrome, sleep disorders, spinal cord disorders, stroke, sydenham'schorea, tourette syndrome, nervous system trauma and injuries, etc.

Furthermore, additional embodiments relate to the use of thecompositions of the invention in the treatment of metabolic disorderssuch as diabetes, obesity, cholesterol level regulation,adrenoleukodystrophy, Krabbe's disease (globoid cell leukodystrophy),metachromatic leukodystrophy, Alexander's disease, Canavan's disease(spongiform leukodystrophy), Pelizaeus-Merzbacher disease, Cockayne'ssyndrome, Hurler's disease, Lowe's syndrome, Leigh's disease, Wilson'sdisease, Hallervorden-Spatz disease, Tay-Sachs disease, etc. The utilityof the compositions of the invention in modulating metabolic processesmay be monitored using any of a variety of techniques known andavailable in the art including, for example, assays which measureadipocyte lipogenesis or adipocyte lipolysis.

In more specific embodiments of the invention, the GlyRS compositions ofthe invention are used to modulate G-protein coupled receptors (GPCRs).The GPCR receptor family consists of three main groups based on theG-protein that is coupled to the receptor (Gs, Gi and Gq). The Gs groupis coupled to activation of adenylate cyclase production of cyclic AMP(cAMP), and the Gi group is coupled to inhibition of adenylate cyclaseproduction of cAMP. Thus, assays to monitor accumulation of cAMP withincells upon treatment with GlyRS compositions of the invention can beused to monitor the activation of two primary groups of G-proteinreceptors.

In other specific embodiments, the GlyRS compositions of the inventionmay be used to modulate cellular signaling, for example, via kinasepathways (e.g., Akt, Erk1/2, and the like). Cell signaling may bemonitored using any of a number of well known assays. For example, theinduction of general cell signaling events can be monitored throughaltered phosphorylation patterns of a variety of target proteins.Detection of cell signaling activities in response to treatment of cellswith GlyRS fragments therefore serves as an indicator of distinctbiological effects. Target proteins used for this assay may be selectedso as to encompass key components of major cellular signaling cascades,thereby providing a broad picture of the cell signaling landscape andits therapeutic relevance. Generally, such assays involve cell treatmentwith GlyRS polypeptides followed by immunodetection with antibodies thatspecifically detect the phosphorylated (activated) forms of the targetproteins.

Illustrative target proteins used for monitoring therapeuticallyrelevant cell signaling events may include, but are not limited to: p38MAPK (mitogen-activated protein kinase; activated by cellular stress andinflammatory cytokines; involved in cell differentiation and apoptosis);SAPK/JNK (stress-activated protein kinase/Jun-amino-terminal kinase;activated by cellular stresses and inflammatory cytokines); Erk1/2,p44/42 MAPK (mitogen-activated protein kinase Erk1 and Erk2; activatedby wide variety of extracellular signals; involved in regulation of cellgrowth and differentiation); and Akt (activated by insulin and variousgrowth or survival factors; involved in inhibition of apoptosis,regulation of glycogen synthesis, cell cycle regulation and cellgrowth). General phosphorylation of tyrosine residues may also bemonitored as a general indicator of changes in cell signaling mediatedby phosphorylation.

Of course, it will be recognized that other classes of proteins, such ascell adhesion molecules (e.g., cadherins, integrins, claudins, catenins,selectins, etc.) and/or ion channel proteins may also be assayed formonitoring cellular events or activities modulated by the compositionsof the invention.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to one of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims. The following examples are provided byway of illustration only and not by way of limitation. Those of skill inthe art will readily recognize a variety of noncritical parameters thatcould be changed or modified to yield essentially similar results.

Example 1 Generation of Human Glycyl-tRNA Synthetase (GlyRS) Fragments

Full-length recombinant human GlyRS having an amino acid sequence as setforth in SEQ ID NO: 1 was expressed and purified from E. coli usingnickel IMAC chromatography. To generate fragments of GlyRS by controlledproteolysis, the full-length protein was treated with 167 nM humanneutrophil elastase for 30 minutes before separation of the fragments bySDS-PAGE (FIGS. 1A-D).

Example 2 GlyRS Fragments Activate Akt and Gi-GPCRs in Endothelial Cells

Pools of GlyRS fragments were generated by adding 25 ng neutrophilelastase to 4 ug full-length recombinant GlyRS for 30 minutes at 37° C.Reactions were stopped by the addition of alpha 1-antitrypsin (SerpinA1) in 10-fold excess of the protease. Bovine aortic endothelial cells(bAEC) were treated with pools of 50 nM full-length GlyRS proteinuncleaved or cleaved with neutrophil elastase. Cells were incubated withGlyRS fragments for 10 minutes, harvested and subjected to westernblotting with an antibody that specifically recognizes only thephosphorylated (activated) form of the signaling molecule Akt. Thistreatment resulted in strong, reproducible activation of Akt viaphosphorylation (FIG. 2A). This effect is significant due to the role ofAkt in inhibition of apoptosis, regulation of glycogen synthesis, cellcycle regulation, and cell growth.

The ability of the pool of GlyRS fragments generated by cleavage withneutrophil elastase to activate G-protein coupled receptors onendothelial cells was also assessed. The GPCR receptor family consistsof three main groups based on the G-protein that is coupled to thereceptor (Gs, Gi and Gq). The Gs group is coupled to activation ofadenylate cyclase production of cyclic AMP (cAMP), and the Gi group iscoupled to inhibition of adenylate cyclase production of cAMP. Thus, theaccumulation of cAMP in endothelial cells in response to treatment withGlyRS fragments was assessed (Gs-GPCR signaling), as well as the abilityof the fragments to inhibit forskolin-induced increases in cAMP(Gi-GPCR). Upon treatment of endothelial cells with 25 and 100 nMcleaved GlyRS fragments, a significant increase in the inhibition offorskolin-stimulated cAMP production was observed (˜35% and ˜40%respectively, FIG. 2B) as compared to treatment with 25 and 100 nMuncleaved GlyRS (˜10%) over PBS alone, indicating activation ofGi-GPCRs. There was no stimulation of cAMP production upon treatment ofendothelial cells with either uncleaved or cleaved GlyRS.

Example 3 GlyRS Fragments Activate Erk1/2 (p44/42 MAPK) Signaling inMonocyte Cells

Pools of GlyRS fragments were generated by adding 25 ng neutrophilelastase to 4 ug full-length recombinant GlyRS for 30 minutes at 37° C.Reactions were stopped by the addition of alpha 1-antitrypsin (SerpinA1) in 10-fold excess of the protease. Monocytes (THP-1) were treatedwith pools of 50 nM full-length GlyRS protein uncleaved or cleaved withneutrophil elastase. Cells were incubated with GlyRS fragments for 0.5,2, 5, 10, 30, and 60 minutes, harvested and subjected to westernblotting with an antibody that specifically recognizes only thephosphorylated (activated) form of the signaling molecules Erk1/2(mitogen-activated protein kinase Erk1 and Erk2). This treatmentresulted in strong, reproducible activation of Erk1/2 viaphosphorylation (FIG. 3) that was strongest after 2 minutes oftreatment. This effect is significant due to the fact that Erk1/2 isactivated by wide variety of extracellular signals, and plays asignificant role in regulation of cell growth and differentiation.

Example 4 Identification of Neutrophil Elastase Cleavage Sites on GlyRS

Fragments generated by cleavage with neutrophil elastase (FIG. 1D) wereanalyzed using LC/MS/MS to determine accurate masses for each fragment.In addition individual fragments were excised from an SDS-PAGE gel andsubjected to in-gel trypsin digestion followed by LC/MS/MS analysis toidentify the portion of the full-length protein from which the fragmentwas generated and to identify non-trypsin cleavage sites that could beattributed to neutrophil elastase.

The identity of these peptide boundaries is summarized in Table 1;residues in bold are non-trypsin cleavage sites indicating that theexact cleavage site of elastase (thus exact N- or C-terminus) of thatfragment has been identified.

TABLE 1 GlyRS peptide boundaries Whole Protease N-term. C-term.Non-tryptic mass (Da) used boundary boundary peptide found  1 71384 NoA57 E685 protease  2 50782 No P239 E685 PGYLRPETAQGIFLNFK protease(SEQ ID NO: 3)  3 53406 elastase T214 E685 TGNDLSPPVSFNLMFK(SEQ ID NO: 4)  4  41000- elastase F311-L338 E685 43000  5 28096elastase N439 E685 ₄₃₉ NVVQFEPSK (SEQ ID NO: 5)  6 25328 elastase T214V438 TGNDLSPPVSFNLMFK (SEQ ID NO: 4) ₄₃₉ NVVQFEPSK (SEQ ID NO: 5)  722398 elastase T214 R420 TGNDLSPPVSFNLMFK (SEQ ID NO: 4)  8 19783elastase L511 E685 LYVEEVVPNVIEPSFGLGR (SEQ ID NO: 6)  9 elastase T214325-338 TGNDLSPPVSFNLMFK (SEQ ID NO: 4) 10  4841 elastase A85 T127AIYGGVSGLYDFGPVGC ALK (SEQ ID NO: 7) QHFIQEEQILEIDCT (SEQ ID NO: 8) 11 3675 elastase R25 I56

FIG. 4A depicts an overview of the above process for identifying GlyRSpeptide boundaries. FIG. 4B shows an illustration of the structure ofthe GlyRS fragment G6, corresponding to amino acids 214-438, within thecrystal structure of full length human GlyRS dimer.

Example 5 GlyRS Fragment G6 Binds to Endothelial Cells

Full length GlyRS and GlyRS fragments were used in a binding assay onbAEC cells. Cells were split into 96-well plates at 30,000 cells/wellovernight. The following day, media was removed and 50 ul/well Z-Fix wasadded to each well. Cells were incubated at room temperature for 15minutes. Wells were aspirated and washed once with 1×PBST. Cells wereblocked with 50 ul/well of 1% BSA/PBS for 1-2 hours at room temperature.The blocking solution was removed from the cells and protein samplesdiluted in 1% BSA/PBS were added to the wells. Samples were incubated atroom temperature for 1 hour. Wells were washed once in 1×PBST.Anti-6×-His HRP (R&D #MAB050H) was added at 50 ul/well diluted 1:500 in1% BSA/PBS. The antibody incubation lasted 30 minutes at roomtemperature. Wells were washed 3 times in 1×PBST. Protein binding wasdetected with 50 ul/well of a 1:1 dilution TMB solution (Thermo #34021).The reaction was quenched by the addition of 50 ul/well 2M sulfuric acidand absorbance was read at 405 nm on a plate reader.

The results of this study, as presented in FIG. 5, demonstrate that theGlyRS fragment G6, corresponding to amino acids 214-438, binds toendothelial cells.

Example 6 A. GlyRS Fragment G6 Migrates THP-1 Monocytes and is Inhibitedby Pertussis Toxin

THP-1 monocyte cells were cultured in complete medium at 6×10⁵ cells perwell. Cells were washed with serum free media and incubated with CalceinAM (1 mg/ml) at a final concentration of 2 ug/ml. Cells were returned tothe incubator for 30 minutes. Cells were washed again and plated intoupper chamber of cell culture dishes at concentration of 6×10⁶ cells/ml.Control chemokines as well as Fragment G6 (200 nM) were added to thelower chamber for 80 minutes to 2 hours. Cells were collected from thelower chamber by pipetting up and down. Fluorescence was read on a platereader at Ex485/Em538 with 530 nm cutoff.

The results of this study, as shown in FIG. 6, demonstrate that G6affects the migration monocyte cells.

B. GlyRS Fragment G6 Signals Through Select Chemokine Receptors

Chemokine receptor screening was performed using the PathHunterβ-Arrestin assay (DiscoveRx Corporation) which monitors the activationof a GPCR in a homogenous, nonimaging assay format using a technologycalled complementation. This technology utilizes an enzyme fragmentcomplementation (EFC) assay with β-galactosidase (β-Gal) as thefunctional reporter. The enzyme is split into two complementary portionsexpressed as fusion proteins in the cell. The Enzyme Acceptor (EA) isfused to β-Arrestin and the ProLink donor peptide is fused to the GPCRof interest. Upon GPCR stimulation, β-Arrestin is recruited to thereceptor for desensitization, bringing the two fragments of β-Galtogether and allowing complementation to occur. This generates an activeenzyme that can convert a chemiluminescent substrate and generates anoutput signal detectable on a standard microplate reader. PathHuntercell lines were expanded from freezer stocks in T25 flasks according tostandard procedures and maintained in selective growth media prior toassay. Once it was established that the cells were healthy and growingnormally, cells were passaged from flasks using trypsin-free celldissociation buffer and seeded into white walled clear bottom 384—wellmicroplates for Fragment G6 profiling. For profiling, cells were seededat a density of 5000 cells per well in a total volume of 20 μL and wereallowed to adhere and recover overnight prior to Fragment G6 addition.Cells were incubated in the presence of 500 nM Fragment G6 at 37° C. for90 minutes. Fifteen chemokine receptor cell lines were tested at 500 nMfinal concentration. Control wells contained 1% vehicle which wascomposed of 50% glycerol, 2 mM DTT, 0.5×PBS.

The results of this study, as shown in FIG. 6 (inset), demonstrate thatGlyRS fragment G6 signals through select chemokine receptors.

Example 7 Fragment G6 Affects Colony Formation of MegakaryocyteProgenitors

This study evaluated the effect of Fragment G6 (500 nM) on humanmegakaryocytic progenitor proliferation. Clonogenic progenitors ofmegakaryocyte (CFU-Mk) lineage were assessed in serum-freecollagen-based medium MegaCult-C® 4950 supplemented with optimalproprietary concentrations of cytokines. Normal human bone marrow lightdensity cells (Lonza lot #07B21195) were stored at −152° C. untilrequired for the assay. On the day of the experiment, the cells werethawed rapidly at 37° C., the contents of the vial were diluted in 10 mLof Iscove's modified Dulbecco's medium (IMDM) containing 2% fetal bovineserum (FBS) and washed by centrifugation (1200 r.p.m. for 10 minutes,room temperature). The supernatant was discarded and the cell pelletresuspended in a known volume of IMDM containing 2% FBS. Fragment G6 wasadded to tubes of serum free collagen-based media MegaCult-C® 4950supplemented with cytokines rhTpo, rhIL-3, and rhIL-6 at optimalproprietary concentrations. Buffer control cultures (containing no testprotein but equivalent concentrations of dialyzed 50% glycerol/0.5×PBS/2mM DTT buffer) were also initiated. Bone marrow cells were then added toeach tube of media to give a final concentration of 1×10⁵ cells perslide. Bovine collagen was then added, tubes were vortexed, and contentsdispensed into triplicate double chamber slides. All cultures wereincubated for 10-12 days at 37° C., 5% CO₂. Following incubation,cultures were assessed microscopically for colony formation prior todehydration and fixation of the slide. Using an antibody stainingprotocol to detect GPIIa/IIIb (CD41) expression, the colonies on theslide were stained using an alkaline phosphatase detection system.Colony numbers were scored and assessed. The colonies were divided intothe following categories, based on size and morphology; CFU-Mk small(2-20), CFU-Mk medium (21-49), CFU-Mk large (>50).

FIG. 7A shows representative stainings of CD41+ colonies. FIG. 7B showsthe results of quantitation of small, medium and large colonies. Theresults of this study demonstrate that GlyRS fragment G6 affects colonyformation of megakaryocyte progenitor cells.

Example 8 Fragments G6 and G6-3 Activate Monocytes

A. GlyRS Fragment Induces CD71 Marker Upregulation in Monocytes

Peripheral blood mononuclear cells (PBMC's) were isolated from a normalblood donor. 1.5×10⁶ PBMC's were treated with a 200 nM dose of the GlyRSfragment G6-3 (consisting of residues 367-438) for 24 hours. PBMC's weretreated with 1 ug/mL of the plant lectin phytohemagglutinin (PHA), and0.1 ug/mL of the protein toxin staphylococcal enterotoxin B (SEB) aspositive controls. As shown in FIG. 8, upregulation of the CD71proliferation marker was seen in the G6-3 treated monocytes afterstaining with the anti-CD71-FITC antibody from Becton-Dickinson andanalysis by flow cytometry. There was no significant increase in CD71upregulation in the gated lymphocyte population of the same samples.

Thus, here we have demonstrated that G6-3 has a cell type specificability to activate monocytes in a PBMC mixture.

B. GlyRS Fragment Induces CD80 Marker Upregulation in Monocytes

Peripheral blood mononuclear cells (PBMC's) were isolated from a normalblood donor. 1.5×10⁶ PBMC's were treated with a 200 nM dose of the GlyRSfragments G6 (consisting of residues 214-438) and G6-3 (367-438) for 24hours. PBMC's were treated with 1 ug/mL of the plant lectinphytohemagglutinin (PHA), and 0.1 ug/mL of the protein toxinstaphylococcal enterotoxin B (SEB) as positive controls. As shown inFIG. 9, upregulation of the CD80 activation marker was seen in the G6-3treated monocytes after staining with the anti-CD80-FITC antibody fromBecton-Dickinson and analysis by flow cytometry. There was nosignificant increase in CD80 upregulation in the gated lymphocytepopulation of the same samples.

The results of this study demonstrate that two GlyRS fragments, G6 andG6-3, activate monocytes in a PBMC mixture in cell type specific manner.

Example 9 Full-Length GlyRS and a Fragment of GlyRS G6 Induces Secretionof Cytokines from PBMCs

Full length GlyRS (100 nM) or a fragment of GlyRS (residues 214-438), G6(100 nM), were incubated with 1×10⁶ Peripheral Blood Mononuclear Cells(PBMC) for 4 hours. After 4 hours of incubation, supernatants wereharvested and snap frozen in liquid nitrogen. Samples were then analyzedby multiplex cytokine analysis (MD Biosciences; St. Paul, Minn.).Supernatants were measured for 27 distinct cytokines and graphed as foldchange as compared to buffer-treated PBMC supernatants. Error bars arerepresentative of 2 biological replicates. As shown in FIG. 10, bothfull-length GlyRS and the G6 fragment showed a large stimulation ofnumerous cytokines above cells treated with PBS (e.g., TNF-α, IL1-β,IL-6, IL-8, IL-10, IL-12p40, MIP1-α, MIP-1β, GRO-α, MCP-1, and IL-1ra).

The results of this study demonstrate that GlyRS polypeptides of theinvention can induce secretion of multiple cytokines of therapeuticrelevance.

Example 10 GlyRS Fragment G6 and G6-3 Induce Migration of RAW264.7 MouseLeukaemic Macrophage Cells

To assess cell migration in vitro, 24-well Transwell chambers withpolycarbonate membranes (5 μm pore size, Costar) were coated with 0.5mg/ml gelatin in PBS and allowed to air dry. Detached RAW264.7 cells(mouse monocyte/macrophage cell line) were washed once with fresh DMEMand suspended into 2×10⁷ cells/ml with 0.1% BSA/DMEM. GlyRS fragmentswere diluted with 0.1% BSA/DMEM into different concentration asindicated in FIG. 11. RAW cells were placed to the upper chamber at2×10⁶ cells/100 ul/well. The lower chambers were filled with 500 ul/wellwith GlyRS fragment. After 24 hours, 37° C. migration, calcein AM(Invitrogen) was added to lower chambers into final 8 uM as cellindicator. 30 minutes later, nonmigrant cells were removed from theupper surface of the Transwell membrane with a cotton swab. Migratingcells on the lower membrane surface were counted under fluorescencemicroscope in high power fields.

The results of this study, as shown in FIG. 11, demonstrate that G6 andG6-3 can induce macrophage cell migration.

Example 11 GlyRS Fragment G6 Induces Migration of HL-60 PromyelocyticLeukemia Cells

HL60 cells (human promyelocytic leukemia cell line) were washed twicewith 0.1% BSA-RPMI. Calcein AM (Invitrogen) was added at 8 uM in 0.1%BSA-RPMI to incubate HL60 cells for 3 hours at 37 C. After one more timeof wash, cells were suspended into 1×10⁷ cells/ml with 0.1% BSA-RPMI.GRS or its fragment was diluted with 0.1% BSA-RPMI into differentconcentration as indicated in FIG. 11. HL60 cells were placed to theupper chamber of Transwell Permeable Support with polycarbonatemembranes (5 um pore size, Costar) at 1×10⁶ cells/100 ul/well. The lowerchambers were filled with 500 ul/well with GRS or fragment. After 30minutes, 37° C. migration, migrated cells in the lower chamber weredetermined by fluorescence reading at Ex485/Em538.

The results of this study, as shown in FIG. 12, demonstrate that G6 caninduce promyelocytic leukemia cell migration.

Example 12 Secretion of Full-Length GlyRS and Fragments from RAW264.7Mouse Leukaemic Macrophage Cells

A. Endogenous Secretion of Full-Length GlyRS from RAW263.7 Cells

RAW cells (mouse monocyte/macrophage cell line) were grown in 6 welltissue culture dishes until confluence. After two washes with PBS, cellswere incubated 48 hours with serum-free DMEM (2 ml/flask) alone, orsupplemented with TNFα or IFN-γ. The conditioned medium was collectedand centrifuged at 20,000×G for 30 minutes at 4 C to remove cell debris.The supernatant was precipitated with TCA at 10% concentration for 20minutes. After an acetone wash, the protein pellet was dissolved intoSDS-sample buffer for SDS-PAGE. Mouse polyclonal antibody against humanGRS (Abnova) detected GlyRS in both the cell lysate and media,indicating endogenous secretion of full-length GlyRS from mousemacrophages (FIG. 13).

B. Full-Length and Fragments of GlyRS are Secreted from RAW264.7 MouseLeukaemic Macrophage Cells Upon Treatment with Lipopolysaccharide

RAW264.7 cells (mouse monocyte/macrophage cell line) were grown in 6well tissue culture dishes until confluence. After two washes with PBS,cells were incubated 48 hours with serum-free DMEM (2 ml/flask) plus LPS10 ng/ml. The conditioned medium was collected and centrifuged at20,000×G for 30 minutes at 4 C to remove cell debris. The supernatantwas precipitated with TCA at 10% concentration for 20 minutes. After anacetone wash, the protein pellet was dissolved into SDS-sample bufferfor SDS-PAGE. Mouse polyclonal antibody against human GRS (Abnova)detected GlyRS in both the cell lysate and media. Upon LPS treatment,specific fragments of GlyRS were observed in the secreted media but notin the cell lysate, indicating the creation and secretion of these GlyRSfragments upon LPS treatment (FIG. 14).

C. Identification of GlyRS Fragments Secreted from LPS-Treated MouseMacrophage Cells by LC/MS/MS

RAW246.7 cells (mouse monocyte/macrophage cell line) were grown in T25flasks until confluence. Using the conditions outlined in above in B,cells were induced to secrete GlyRS fragments using LPS. The conditionedmedium was collected and centrifuged at 20,000×G for 30 min at 4 C toremove cell debris. The supernatant (CM) was precipitated with TCA at10% concentration for 20 minutes. After an acetone wash, the proteinpellet was dissolved into SDS-sample buffer for SDS-PAGE. Individualfragments were excised from the SDS-PAGE gel and subjected to in-geltrypsin digestion followed by LC/MS/MS analysis to identify the portionof the full-length protein from which the fragment was generated (FIG.15). Peptides identified from the fragment of ˜40-50 kDa were locatedwithin the catalytic domain of the protein (see FIGS. 15, 16A) and basedon theoretical molecular weight calculations, indicate this fragmentlikely represents a protein truncated at the N-terminus corresponding toamino acid residues from about 265-685 of GlyRS. Peptides identifiedfrom the fragment of ˜15 kDa were located within the C-terminus of theprotein (FIGS. 15, 16B) and based on theoretical molecular weightcalculations, indicate this fragment likely represents the c-terminalportion of the protein corresponding to amino acid residues from about483-685 of GlyRS

As noted, the disclosure above is descriptive, illustrative andexemplary and is not to be taken as limiting the scope defined by theappended claims which follow.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

The invention claimed is:
 1. A method for treating a conditioncomprising administering to a subject in need thereof a therapeuticcomposition, comprising a pharmaceutically-acceptable carrier and anisolated glycyl-tRNA synthetase (GRS) polypeptide selected from (a) apolypeptide that comprises SEQ ID NO:1, (b) a fragment of (a) comprisingat least 600 contiguous amino acids of SEQ ID NO:1, and (c) a variant of(a) having at least 95% identity to SEQ ID NO:1, where the GRSpolypeptide has cell signaling activity and is at least about 90% pure,where the composition is sterile and pyrogen-free, and where thecondition is selected from the group consisting of inflammatorydiseases, autoimmune diseases, neoplastic diseases, metabolic diseases,neurological diseases, infections, cardiovascular diseases, and diseasesassociated with abnormal angiogenesis.
 2. The method of claim 1, wherethe inflammatory disease is selected from the group consisting ofprimary immunodeficiencies, immune mediated thrombocytopenia, Kawasakisyndrome, chronic inflammatory demyelinating polyneuropathy, andtransfusion purpura.
 3. The method of claim 1, where the autoimmunedisease is selected from the group consisting of Guillain-Barresyndrome, autoimmune hemolytic anemia, thrombocytopenia,transplantation, myasthenia gravis, dermatomyositis, polymyositis,autoimmune hemolytic anemia, autoimmune neonatal thrombocytopenia,idiopathic thrombocytopenia purpura, autoimmunocytopenia, hemolyticanemia, antiphospholipid syndrome, dermatitis, allergicencephalomyelitis, myocarditis, relapsing polychondritis, rheumaticheart disease, glomerulonephritis, multiple sclerosis, neuritis, uveitisophthalmia, polyendocrinopathies, Reiter's disease, stiff-man syndrome,autoimmune pulmonary inflammation, insulin dependent diabetes mellitis,autoimmune inflammatory eye disease, rhenmatoid arthritis, scleroderma,Sjogren's syndrome, and inflammatory myopathies.
 4. The method of claim1, where the neoplastic disease is selected from the group consisting ofcolon cancer, cardiac tumors, pancreatic cancer, melanoma,retinoblastoma, glioblastoma, lung cancer, intestinal cancer, testicularcancer, stomach cancer, neuroblastoma, osteosarcoma, chondrosarcoma,adenoma, breast cancer, prostate cancer, Kaposi's sarcoma, ovariancancer, leukemia, myelodyspastic syndrome, polycythemia vera, lymphomas,multiple myeloma, renal cell carcinoma, and solid tumors.
 5. The methodof claim 1, where the metabolic disease is selected from the groupconsisting of diabetes, obesity, cholesterol level regulation,adrenoleukodystrophy, Krabbe's disease, metachromatic leukodystrophy,Alexander's disease, Canavan's disease, Peaeus-Merzbacher disease,Cockayne's syndrome, Hurler's disease, Lowe's syndrome, Leigh's disease,Wilson's disease, Hallervorden-Spatz disease, and Tay-Sach disease. 6.The method of claim 1, where the neurological disease is selected fromthe group consisting of Parkinson's disease, Alzheimer's disease, Pick'sdisease, Creutzfeldt-Jacob disease, Huntington's chorea, alternatinghemiplegia, amyotrophic lateral sclerosis, ataxia, cerebral palsy,chronic fatigue syndrome, and chronic pain syndromes.
 7. The method ofclaim 1, where the disease associated with abnormal angiogenesis isselected from the group consisting of age-related macular degeneration(AMD) cancer, development abnormalities, diabetic blindness,endometriosis, ocular neovascularization, psoriasis, rheumatoidarthritis, skin discolorations, cardiovascular disease, restenosis,tissue damage after reperfusion of ischemic tissue or cardiac failure,chronic inflammation, and wound healing.
 8. A method for modulating acellular activity comprising contacting a cell or tissue with atherapeutic composition, comprising a pharmaceutically-acceptablecarrier and an isolated glycyl-tRNA synthetase (GRS) polypeptideselected from (a) a polypeptide that comprises SEQ ID NO:1, (b) afragment of (a) comprising at least 600 contiguous amino acids of SEQ IDNO:1, and (c) a variant of (a) having at least 95% identity to SEQ IDNO:1, where the GRS polypeptide has cell signaling activity and is atleast about 90% pure, and where the composition is sterile andpyrogen-free.
 9. The method of claim 8, wherein the cellular activity isselected from the group consisting of modulation of cell proliferation,modulation of apoptosis, modulation of cell signaling, modulation ofcell migration, cell metabolism, gene transcription, mRNA translation,cell activation, and modulation of cytokine production and/or release.10. The method of claim 8, wherein the cellular activity is selectedfrom the group consisting of modulation of Akt-mediated cell signaling,modulation of Erk1/2-mediated cell signaling and modulation ofGPCR-mediated cell signaling, modulation of CD71, and modulation ofCD80.
 11. The method of claim 8, wherein the cellular activity ismodulation of cytokine production and/or release, wherein the cytokineis selected from the group consisting of TNF-α, IL1-β, IL-6, IL-8,IL-10, IL-12/p40, MIP1-α, MIP-1β, GRO-α, MCP-1, and IL-1ra.
 12. Themethod of claim 8, wherein the cellular activity is selected from thegroup consisting of cell metabolism, gene transcription, and mRNAtranslation.